diff --git a/.github/workflows/test_tox.yml b/.github/workflows/test_tox.yml
index 4f4aef6..9e02a93 100644
--- a/.github/workflows/test_tox.yml
+++ b/.github/workflows/test_tox.yml
@@ -60,8 +60,8 @@ jobs:
     strategy:
       matrix:
         include:
-        - python-version: '3.11'
-          toxenv: 'py311,coverage'
+        - python-version: '3.10'
+          toxenv: 'coverage'
     container:
       image: ubuntu:22.04
     steps:
diff --git a/config/dpkg/changelog b/config/dpkg/changelog
index 3eaefe9..3a182e5 100644
--- a/config/dpkg/changelog
+++ b/config/dpkg/changelog
@@ -1,5 +1,5 @@
-dfdatetime (20231205-1) unstable; urgency=low
+dfdatetime (20231210-1) unstable; urgency=low
 
   * Auto-generated
 
- -- Log2Timeline maintainers <log2timeline-maintainers@googlegroups.com>  Tue, 05 Dec 2023 05:27:13 +0100
+ -- Log2Timeline maintainers <log2timeline-maintainers@googlegroups.com>  Sun, 10 Dec 2023 10:02:43 +0100
diff --git a/dfdatetime/__init__.py b/dfdatetime/__init__.py
index f1f1aa6..3c9766a 100644
--- a/dfdatetime/__init__.py
+++ b/dfdatetime/__init__.py
@@ -25,4 +25,4 @@
 from dfdatetime import webkit_time
 
 
-__version__ = '20231205'
+__version__ = '20231210'
diff --git a/dfdatetime/apfs_time.py b/dfdatetime/apfs_time.py
index b29bcd7..c074042 100644
--- a/dfdatetime/apfs_time.py
+++ b/dfdatetime/apfs_time.py
@@ -47,7 +47,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
diff --git a/dfdatetime/cocoa_time.py b/dfdatetime/cocoa_time.py
index 90c3c8b..17cb853 100644
--- a/dfdatetime/cocoa_time.py
+++ b/dfdatetime/cocoa_time.py
@@ -78,7 +78,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
@@ -93,7 +93,7 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
-    microseconds = date_time_values.get('microseconds', None)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
     timestamp = self._GetNumberOfSecondsFromElements(
@@ -101,8 +101,7 @@ def CopyFromDateTimeString(self, time_string):
     timestamp += self._COCOA_TO_POSIX_BASE
 
     timestamp = float(timestamp)
-    if microseconds is not None:
-      timestamp += float(microseconds) / definitions.MICROSECONDS_PER_SECOND
+    timestamp += float(nanoseconds) / definitions.NANOSECONDS_PER_SECOND
 
     self._normalized_timestamp = None
     self._timestamp = timestamp
diff --git a/dfdatetime/definitions.py b/dfdatetime/definitions.py
index 071677f..46200f4 100644
--- a/dfdatetime/definitions.py
+++ b/dfdatetime/definitions.py
@@ -9,7 +9,7 @@
 
 DAYS_PER_MONTH = (31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31)
 
-SECONDS_PER_DAY = 24 * 60 * 60
+SECONDS_PER_DAY = 86400
 
 DECISECONDS_PER_SECOND = 10
 
@@ -20,8 +20,11 @@
 MICROSECONDS_PER_DECISECOND = 100000
 MICROSECONDS_PER_MILLISECOND = 1000
 
-NANOSECONDS_PER_MICROSECOND = 1000
+NANOSECONDS_PER_DAY = 86400000000000
 NANOSECONDS_PER_SECOND = 1000000000
+NANOSECONDS_PER_DECISECOND = 100000000
+NANOSECONDS_PER_MILLISECOND = 1000000
+NANOSECONDS_PER_MICROSECOND = 1000
 
 PRECISION_1_DAY = '1d'
 PRECISION_1_HOUR = '1h'
diff --git a/dfdatetime/delphi_date_time.py b/dfdatetime/delphi_date_time.py
index 16a88a3..a844599 100644
--- a/dfdatetime/delphi_date_time.py
+++ b/dfdatetime/delphi_date_time.py
@@ -86,7 +86,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
@@ -101,7 +101,7 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
-    microseconds = date_time_values.get('microseconds', None)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
     if year > 9999:
@@ -112,8 +112,7 @@ def CopyFromDateTimeString(self, time_string):
 
     timestamp = float(timestamp) / definitions.SECONDS_PER_DAY
     timestamp += self._DELPHI_TO_POSIX_BASE
-    if microseconds is not None:
-      timestamp += float(microseconds) / definitions.MICROSECONDS_PER_DAY
+    timestamp += float(nanoseconds) / definitions.NANOSECONDS_PER_DAY
 
     self._normalized_timestamp = None
     self._timestamp = timestamp
diff --git a/dfdatetime/dotnet_datetime.py b/dfdatetime/dotnet_datetime.py
index c76b0f5..73e13c9 100644
--- a/dfdatetime/dotnet_datetime.py
+++ b/dfdatetime/dotnet_datetime.py
@@ -79,7 +79,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
@@ -94,18 +94,19 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
-    microseconds = date_time_values.get('microseconds', 0)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
     if year > 9999:
       raise ValueError(f'Unsupported year value: {year:d}.')
 
+    nanoseconds, _ = divmod(nanoseconds, 100)
+
     timestamp = self._GetNumberOfSecondsFromElements(
         year, month, day_of_month, hours, minutes, seconds)
     timestamp += self._DOTNET_TO_POSIX_BASE
-    timestamp *= definitions.MICROSECONDS_PER_SECOND
-    timestamp += microseconds
-    timestamp *= self._100_NANOSECONDS_PER_MICROSECOND
+    timestamp *= self._100_NANOSECONDS_PER_SECOND
+    timestamp += nanoseconds
 
     self._normalized_timestamp = None
     self._timestamp = timestamp
diff --git a/dfdatetime/fake_time.py b/dfdatetime/fake_time.py
index 83594db..d65133f 100644
--- a/dfdatetime/fake_time.py
+++ b/dfdatetime/fake_time.py
@@ -69,7 +69,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
     """
@@ -81,12 +81,18 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
+    nanoseconds = date_time_values.get('nanoseconds', None)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
     self._normalized_timestamp = None
     self._number_of_seconds = self._GetNumberOfSecondsFromElements(
         year, month, day_of_month, hours, minutes, seconds)
-    self._microseconds = date_time_values.get('microseconds', None)
+
+    if nanoseconds is None:
+      self._microseconds = None
+    else:
+      self._microseconds, _ = divmod(nanoseconds, 1000)
+
     self._time_zone_offset = time_zone_offset
 
   def CopyToDateTimeString(self):
diff --git a/dfdatetime/fat_date_time.py b/dfdatetime/fat_date_time.py
index c5f007a..76c9494 100644
--- a/dfdatetime/fat_date_time.py
+++ b/dfdatetime/fat_date_time.py
@@ -140,7 +140,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
@@ -250,7 +250,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
@@ -265,20 +265,19 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
-    microseconds = date_time_values.get('microseconds', 0)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
     if year < 1980 or year > (1980 + 0x7f):
       raise ValueError(f'Year value not supported: {year!s}.')
 
+    milliseconds, _ = divmod(nanoseconds, 10000000)
+
     timestamp = self._GetNumberOfSecondsFromElements(
         year, month, day_of_month, hours, minutes, seconds)
     timestamp -= self._FAT_DATE_TO_POSIX_BASE
     timestamp *= 100
-
-    if microseconds:
-      milliseconds, _ = divmod(microseconds, 10000)
-      timestamp += milliseconds
+    timestamp += milliseconds
 
     self._timestamp = timestamp
     self._time_zone_offset = time_zone_offset
diff --git a/dfdatetime/filetime.py b/dfdatetime/filetime.py
index c29cacc..3fc6127 100644
--- a/dfdatetime/filetime.py
+++ b/dfdatetime/filetime.py
@@ -83,7 +83,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
@@ -98,17 +98,19 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
     if year < 1601:
       raise ValueError(f'Year value not supported: {year!s}.')
 
+    nanoseconds, _ = divmod(nanoseconds, 100)
+
     timestamp = self._GetNumberOfSecondsFromElements(
         year, month, day_of_month, hours, minutes, seconds)
     timestamp += self._FILETIME_TO_POSIX_BASE
-    timestamp *= definitions.MICROSECONDS_PER_SECOND
-    timestamp += date_time_values.get('microseconds', 0)
-    timestamp *= self._100_NANOSECONDS_PER_MICROSECOND
+    timestamp *= self._100_NANOSECONDS_PER_SECOND
+    timestamp += nanoseconds
 
     self._normalized_timestamp = None
     self._timestamp = timestamp
diff --git a/dfdatetime/golang_time.py b/dfdatetime/golang_time.py
index c34d25a..54346d8 100644
--- a/dfdatetime/golang_time.py
+++ b/dfdatetime/golang_time.py
@@ -161,7 +161,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
@@ -175,7 +175,7 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
-    microseconds = date_time_values.get('microseconds', 0)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
     if year < 0:
@@ -185,7 +185,6 @@ def CopyFromDateTimeString(self, time_string):
         year, month, day_of_month, hours, minutes, seconds)
 
     seconds += self._GOLANG_TO_POSIX_BASE
-    nanoseconds = microseconds * definitions.NANOSECONDS_PER_MICROSECOND
 
     self._normalized_timestamp = None
     self._number_of_seconds = seconds
diff --git a/dfdatetime/hfs_time.py b/dfdatetime/hfs_time.py
index 7a24d86..c817c42 100644
--- a/dfdatetime/hfs_time.py
+++ b/dfdatetime/hfs_time.py
@@ -80,7 +80,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
diff --git a/dfdatetime/interface.py b/dfdatetime/interface.py
index e2287eb..1fc57d1 100644
--- a/dfdatetime/interface.py
+++ b/dfdatetime/interface.py
@@ -342,13 +342,13 @@ def _CopyDateTimeFromString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
     Returns:
       dict[str, int]: date and time values, such as year, month, day of month,
-          hours, minutes, seconds, microseconds, time zone offset in minutes.
+          hours, minutes, seconds, nanoseconds, time zone offset in minutes.
 
     Raises:
       ValueError: if the time string is invalid or not supported.
@@ -372,7 +372,7 @@ def _CopyDateTimeFromString(self, time_string):
       raise ValueError(
           'Invalid time string - space missing as date and time separator.')
 
-    hours, minutes, seconds, microseconds, time_zone_offset = (
+    hours, minutes, seconds, nanoseconds, time_zone_offset = (
         self._CopyTimeFromString(time_string[11:]))
 
     date_time_values = {
@@ -383,8 +383,8 @@ def _CopyDateTimeFromString(self, time_string):
         'minutes': minutes,
         'seconds': seconds}
 
-    if microseconds is not None:
-      date_time_values['microseconds'] = microseconds
+    if nanoseconds is not None:
+      date_time_values['nanoseconds'] = nanoseconds
     if time_zone_offset is not None:
       date_time_values['time_zone_offset'] = time_zone_offset
 
@@ -398,11 +398,11 @@ def _CopyTimeFromString(self, time_string):
           hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The seconds fraction and
+          fraction can be either 3, 6 or 9 digits. The seconds fraction and
           time zone offset are optional.
 
     Returns:
-      tuple[int, int, int, int, int]: hours, minutes, seconds, microseconds,
+      tuple[int, int, int, int, int]: hours, minutes, seconds, nanoseconds,
           time zone offset in minutes.
 
     Raises:
@@ -442,7 +442,7 @@ def _CopyTimeFromString(self, time_string):
     if seconds not in range(0, 60):
       raise ValueError(f'Seconds value: {seconds:d} out of bounds.')
 
-    microseconds = None
+    nanoseconds = None
     time_zone_offset = None
 
     time_zone_string_index = 8
@@ -459,7 +459,7 @@ def _CopyTimeFromString(self, time_string):
 
     if time_string_length > 8 and time_string[8] == '.':
       time_fraction_length = time_zone_string_index - 9
-      if time_fraction_length not in (3, 6):
+      if time_fraction_length not in (3, 6, 9):
         raise ValueError('Invalid time string.')
 
       try:
@@ -469,9 +469,11 @@ def _CopyTimeFromString(self, time_string):
         raise ValueError('Unable to parse time fraction.')
 
       if time_fraction_length == 3:
+        time_fraction *= 1000000
+      elif time_fraction_length == 6:
         time_fraction *= 1000
 
-      microseconds = time_fraction
+      nanoseconds = time_fraction
 
     if time_zone_string_index < time_string_length:
       if (time_string_length - time_zone_string_index != 6 or
@@ -502,7 +504,7 @@ def _CopyTimeFromString(self, time_string):
       if time_string[time_zone_string_index] == '-':
         time_zone_offset = -time_zone_offset
 
-    return hours, minutes, seconds, microseconds, time_zone_offset
+    return hours, minutes, seconds, nanoseconds, time_zone_offset
 
   def _GetDateValues(
       self, number_of_days, epoch_year, epoch_month, epoch_day_of_month):
@@ -870,7 +872,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
diff --git a/dfdatetime/ole_automation_date.py b/dfdatetime/ole_automation_date.py
index 4ec9b36..22602b8 100644
--- a/dfdatetime/ole_automation_date.py
+++ b/dfdatetime/ole_automation_date.py
@@ -84,7 +84,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
@@ -99,15 +99,14 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
-    microseconds = date_time_values.get('microseconds', None)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
     timestamp = self._GetNumberOfSecondsFromElements(
         year, month, day_of_month, hours, minutes, seconds)
 
     timestamp = float(timestamp)
-    if microseconds is not None:
-      timestamp += float(microseconds) / definitions.MICROSECONDS_PER_SECOND
+    timestamp += float(nanoseconds) / definitions.NANOSECONDS_PER_SECOND
 
     timestamp /= definitions.SECONDS_PER_DAY
     timestamp += self._OLE_AUTOMATION_DATE_TO_POSIX_BASE
diff --git a/dfdatetime/posix_time.py b/dfdatetime/posix_time.py
index a31fd34..d446bb4 100644
--- a/dfdatetime/posix_time.py
+++ b/dfdatetime/posix_time.py
@@ -78,7 +78,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
     """
@@ -175,7 +175,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
     """
@@ -187,17 +187,16 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
-    microseconds = date_time_values.get('microseconds', 0)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
+    milliseconds, _ = divmod(
+        nanoseconds, definitions.NANOSECONDS_PER_MILLISECOND)
+
     timestamp = self._GetNumberOfSecondsFromElements(
         year, month, day_of_month, hours, minutes, seconds)
     timestamp *= definitions.MILLISECONDS_PER_SECOND
-
-    if microseconds:
-      milliseconds, _ = divmod(
-          microseconds, definitions.MILLISECONDS_PER_SECOND)
-      timestamp += milliseconds
+    timestamp += milliseconds
 
     self._timestamp = timestamp
     self._time_zone_offset = time_zone_offset
@@ -282,7 +281,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
     """
@@ -294,13 +293,16 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
-    microseconds = date_time_values.get('microseconds', 0)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
+    milliseconds, _ = divmod(
+        nanoseconds, definitions.NANOSECONDS_PER_MICROSECOND)
+
     timestamp = self._GetNumberOfSecondsFromElements(
         year, month, day_of_month, hours, minutes, seconds)
     timestamp *= definitions.MICROSECONDS_PER_SECOND
-    timestamp += microseconds
+    timestamp += milliseconds
 
     self._timestamp = timestamp
     self._time_zone_offset = time_zone_offset
@@ -385,7 +387,7 @@ def _CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
     """
@@ -397,16 +399,13 @@ def _CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
-    microseconds = date_time_values.get('microseconds', None)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
     timestamp = self._GetNumberOfSecondsFromElements(
         year, month, day_of_month, hours, minutes, seconds)
     timestamp *= definitions.NANOSECONDS_PER_SECOND
-
-    if microseconds:
-      nanoseconds = microseconds * definitions.MILLISECONDS_PER_SECOND
-      timestamp += nanoseconds
+    timestamp += nanoseconds
 
     self._normalized_timestamp = None
     self._timestamp = timestamp
@@ -420,7 +419,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
     """
diff --git a/dfdatetime/precisions.py b/dfdatetime/precisions.py
index 9a79274..108ca1b 100644
--- a/dfdatetime/precisions.py
+++ b/dfdatetime/precisions.py
@@ -18,11 +18,11 @@ class DateTimePrecisionHelper(object):
   # pylint: disable=missing-raises-doc,redundant-returns-doc
 
   @classmethod
-  def CopyMicrosecondsToFractionOfSecond(cls, microseconds):
-    """Copies the number of microseconds to a fraction of second value.
+  def CopyNanosecondsToFractionOfSecond(cls, nanoseconds):
+    """Copies the number of nanoseconds to a fraction of second value.
 
     Args:
-      microseconds (int): number of microseconds.
+      nanoseconds (int): number of nanoseconds.
 
     Returns:
       decimal.Decimal: fraction of second, which must be a value between 0.0
@@ -52,22 +52,22 @@ class SecondsPrecisionHelper(DateTimePrecisionHelper):
   """Seconds precision helper."""
 
   @classmethod
-  def CopyMicrosecondsToFractionOfSecond(cls, microseconds):
-    """Copies the number of microseconds to a fraction of second value.
+  def CopyNanosecondsToFractionOfSecond(cls, nanoseconds):
+    """Copies the number of nanoseconds to a fraction of second value.
 
     Args:
-      microseconds (int): number of microseconds.
+      nanoseconds (int): number of nanoseconds.
 
     Returns:
       decimal.Decimal: fraction of second, which must be a value between 0.0 and
           1.0. For the seconds precision helper this will always be 0.0.
 
     Raises:
-      ValueError: if the number of microseconds is out of bounds.
+      ValueError: if the number of nanoseconds is out of bounds.
     """
-    if microseconds < 0 or microseconds >= definitions.MICROSECONDS_PER_SECOND:
+    if nanoseconds < 0 or nanoseconds >= definitions.NANOSECONDS_PER_SECOND:
       raise ValueError(
-          f'Number of microseconds value: {microseconds:d} out of bounds.')
+          f'Number of nanoseconds value: {nanoseconds:d} out of bounds.')
 
     return decimal.Decimal(0.0)
 
@@ -103,25 +103,25 @@ class MillisecondsPrecisionHelper(DateTimePrecisionHelper):
   """Milliseconds precision helper."""
 
   @classmethod
-  def CopyMicrosecondsToFractionOfSecond(cls, microseconds):
-    """Copies the number of microseconds to a fraction of second value.
+  def CopyNanosecondsToFractionOfSecond(cls, nanoseconds):
+    """Copies the number of nanoseconds to a fraction of second value.
 
     Args:
-      microseconds (int): number of microseconds.
+      nanoseconds (int): number of nanoseconds.
 
     Returns:
       decimal.Decimal: fraction of second, which must be a value between 0.0 and
           1.0.
 
     Raises:
-      ValueError: if the number of microseconds is out of bounds.
+      ValueError: if the number of nanoseconds is out of bounds.
     """
-    if microseconds < 0 or microseconds >= definitions.MICROSECONDS_PER_SECOND:
+    if nanoseconds < 0 or nanoseconds >= definitions.NANOSECONDS_PER_SECOND:
       raise ValueError(
-          f'Number of microseconds value: {microseconds:d} out of bounds.')
+          f'Number of nanoseconds value: {nanoseconds:d} out of bounds.')
 
     milliseconds, _ = divmod(
-        microseconds, definitions.MICROSECONDS_PER_MILLISECOND)
+        nanoseconds, definitions.NANOSECONDS_PER_MILLISECOND)
     return decimal.Decimal(milliseconds) / definitions.MILLISECONDS_PER_SECOND
 
   @classmethod
@@ -157,23 +157,25 @@ class MicrosecondsPrecisionHelper(DateTimePrecisionHelper):
   """Microseconds precision helper."""
 
   @classmethod
-  def CopyMicrosecondsToFractionOfSecond(cls, microseconds):
-    """Copies the number of microseconds to a fraction of second value.
+  def CopyNanosecondsToFractionOfSecond(cls, nanoseconds):
+    """Copies the number of nanoseconds to a fraction of second value.
 
     Args:
-      microseconds (int): number of microseconds.
+      nanoseconds (int): number of nanoseconds.
 
     Returns:
       decimal.Decimal: fraction of second, which must be a value between 0.0 and
           1.0.
 
     Raises:
-      ValueError: if the number of microseconds is out of bounds.
+      ValueError: if the number of nanoseconds is out of bounds.
     """
-    if microseconds < 0 or microseconds >= definitions.MICROSECONDS_PER_SECOND:
+    if nanoseconds < 0 or nanoseconds >= definitions.NANOSECONDS_PER_SECOND:
       raise ValueError(
-          f'Number of microseconds value: {microseconds:d} out of bounds.')
+          f'Number of nanoseconds value: {nanoseconds:d} out of bounds.')
 
+    microseconds, _ = divmod(
+        nanoseconds, definitions.NANOSECONDS_PER_MICROSECOND)
     return decimal.Decimal(microseconds) / definitions.MICROSECONDS_PER_SECOND
 
   @classmethod
@@ -205,12 +207,65 @@ def CopyToDateTimeString(cls, time_elements_tuple, fraction_of_second):
             f'{hours:02d}:{minutes:02d}:{seconds:02d}.{microseconds:06d}')
 
 
+class NanosecondsPrecisionHelper(DateTimePrecisionHelper):
+  """Nanoseconds precision helper."""
+
+  @classmethod
+  def CopyNanosecondsToFractionOfSecond(cls, nanoseconds):
+    """Copies the number of nanoseconds to a fraction of second value.
+
+    Args:
+      nanoseconds (int): number of nanoseconds.
+
+    Returns:
+      decimal.Decimal: fraction of second, which must be a value between 0.0 and
+          1.0.
+
+    Raises:
+      ValueError: if the number of nanoseconds is out of bounds.
+    """
+    if nanoseconds < 0 or nanoseconds >= definitions.NANOSECONDS_PER_SECOND:
+      raise ValueError(
+          f'Number of nanoseconds value: {nanoseconds:d} out of bounds.')
+
+    return decimal.Decimal(nanoseconds) / definitions.NANOSECONDS_PER_SECOND
+
+  @classmethod
+  def CopyToDateTimeString(cls, time_elements_tuple, fraction_of_second):
+    """Copies the time elements and fraction of second to a string.
+
+    Args:
+      time_elements_tuple (tuple[int, int, int, int, int, int]):
+          time elements, contains year, month, day of month, hours, minutes and
+          seconds.
+      fraction_of_second (decimal.Decimal): fraction of second, which must be a
+          value between 0.0 and 1.0.
+
+    Returns:
+      str: date and time value formatted as:
+          YYYY-MM-DD hh:mm:ss.######
+
+    Raises:
+      ValueError: if the fraction of second is out of bounds.
+    """
+    if fraction_of_second < 0.0 or fraction_of_second >= 1.0:
+      raise ValueError(
+          f'Fraction of second value: {fraction_of_second:f} out of bounds.')
+
+    year, month, day_of_month, hours, minutes, seconds = time_elements_tuple
+    nanoseconds = int(fraction_of_second * definitions.NANOSECONDS_PER_SECOND)
+
+    return (f'{year:04d}-{month:02d}-{day_of_month:02d} '
+            f'{hours:02d}:{minutes:02d}:{seconds:02d}.{nanoseconds:09d}')
+
+
 class PrecisionHelperFactory(object):
   """Date time precision helper factory."""
 
   _PRECISION_CLASSES = {
       definitions.PRECISION_1_MICROSECOND: MicrosecondsPrecisionHelper,
       definitions.PRECISION_1_MILLISECOND: MillisecondsPrecisionHelper,
+      definitions.PRECISION_1_NANOSECOND: NanosecondsPrecisionHelper,
       definitions.PRECISION_1_SECOND: SecondsPrecisionHelper}
 
   @classmethod
diff --git a/dfdatetime/rfc2579_date_time.py b/dfdatetime/rfc2579_date_time.py
index e404871..d137466 100644
--- a/dfdatetime/rfc2579_date_time.py
+++ b/dfdatetime/rfc2579_date_time.py
@@ -193,7 +193,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
@@ -208,11 +208,11 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
-    microseconds = date_time_values.get('microseconds', 0)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
     deciseconds, _ = divmod(
-        microseconds, definitions.MICROSECONDS_PER_DECISECOND)
+        nanoseconds, definitions.NANOSECONDS_PER_DECISECOND)
 
     if year < 0 or year > 65536:
       raise ValueError(f'Unsupported year value: {year:d}.')
diff --git a/dfdatetime/systemtime.py b/dfdatetime/systemtime.py
index 760e7b5..d37b135 100644
--- a/dfdatetime/systemtime.py
+++ b/dfdatetime/systemtime.py
@@ -168,7 +168,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
@@ -183,11 +183,11 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
-    microseconds = date_time_values.get('microseconds', 0)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
     milliseconds, _ = divmod(
-        microseconds, definitions.MICROSECONDS_PER_MILLISECOND)
+        nanoseconds, definitions.NANOSECONDS_PER_MILLISECOND)
 
     if year < 1601 or year > 30827:
       raise ValueError(f'Unsupported year value: {year:d}.')
diff --git a/dfdatetime/time_elements.py b/dfdatetime/time_elements.py
index 4f035c1..b9a3f0c 100644
--- a/dfdatetime/time_elements.py
+++ b/dfdatetime/time_elements.py
@@ -138,12 +138,12 @@ def _CopyDateTimeFromStringISO8601(self, time_string):
           hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The fraction of second and
+          fraction can be either 3, 6 or 9 digits. The fraction of second and
           time zone offset are optional.
 
     Returns:
       dict[str, int]: date and time values, such as year, month, day of month,
-          hours, minutes, seconds, microseconds, time zone offset in minutes.
+          hours, minutes, seconds, nanoseconds, time zone offset in minutes.
 
     Raises:
       ValueError: if the time string is invalid or not supported.
@@ -166,7 +166,7 @@ def _CopyDateTimeFromStringISO8601(self, time_string):
     if time_string[10] != 'T':
       raise ValueError('Invalid time string - missing date and time separator.')
 
-    hours, minutes, seconds, microseconds, time_zone_offset = (
+    hours, minutes, seconds, nanoseconds, time_zone_offset = (
         self._CopyTimeFromStringISO8601(time_string[11:]))
 
     date_time_values = {
@@ -177,8 +177,8 @@ def _CopyDateTimeFromStringISO8601(self, time_string):
         'minutes': minutes,
         'seconds': seconds}
 
-    if microseconds is not None:
-      date_time_values['microseconds'] = microseconds
+    if nanoseconds is not None:
+      date_time_values['nanoseconds'] = nanoseconds
     if time_zone_offset is not None:
       date_time_values['time_zone_offset'] = time_zone_offset
 
@@ -349,7 +349,7 @@ def _CopyFromDateTimeValues(self, date_time_values):
 
     Args:
       date_time_values  (dict[str, int]): date and time values, such as year,
-          month, day of month, hours, minutes, seconds, microseconds, time zone
+          month, day of month, hours, minutes, seconds, nanoseconds, time zone
           offset in minutes.
     """
     year = date_time_values.get('year', 0)
@@ -375,11 +375,11 @@ def _CopyTimeFromStringISO8601(self, time_string):
           hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The faction of second and
+          fraction can be either 3, 6 or 9 digits. The fraction of second and
           time zone offset are optional.
 
     Returns:
-      tuple[int, int, int, int, int]: hours, minutes, seconds, microseconds,
+      tuple[int, int, int, int, int]: hours, minutes, seconds, nanoseconds,
           time zone offset in minutes.
 
     Raises:
@@ -404,7 +404,7 @@ def _CopyTimeFromStringISO8601(self, time_string):
 
     minutes = None
     seconds = None
-    microseconds = None
+    nanoseconds = None
     time_zone_offset = None
 
     time_string_index = 2
@@ -481,8 +481,8 @@ def _CopyTimeFromStringISO8601(self, time_string):
         seconds = int(time_fraction)
         time_fraction -= seconds
 
-      time_fraction *= definitions.MICROSECONDS_PER_SECOND
-      microseconds = int(time_fraction)
+      time_fraction *= definitions.NANOSECONDS_PER_SECOND
+      nanoseconds = int(time_fraction)
 
     if minutes is not None and minutes not in range(0, 60):
       raise ValueError(f'Minutes value: {minutes:d} out of bounds.')
@@ -520,7 +520,7 @@ def _CopyTimeFromStringISO8601(self, time_string):
       if time_string[time_zone_string_index] == '-':
         time_zone_offset = -time_zone_offset
 
-    return hours, minutes, seconds, microseconds, time_zone_offset
+    return hours, minutes, seconds, nanoseconds, time_zone_offset
 
   def _CopyTimeFromStringRFC(self, time_string, time_zone_string):
     """Copies a time from a RFC 822, RFC 1123 or RFC 2822 time string.
@@ -695,7 +695,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
     """
@@ -718,7 +718,7 @@ def CopyFromStringISO8601(self, time_string):
           YYYY-MM-DDThh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
@@ -941,7 +941,7 @@ def _CopyFromDateTimeValues(self, date_time_values):
 
     Args:
       date_time_values  (dict[str, int]): date and time values, such as year,
-          month, day of month, hours, minutes, seconds, microseconds, time zone
+          month, day of month, hours, minutes, seconds, nanoseconds, time zone
           offset in minutes.
 
     Raises:
@@ -953,14 +953,14 @@ def _CopyFromDateTimeValues(self, date_time_values):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
-    microseconds = date_time_values.get('microseconds', 0)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
     precision_helper = precisions.PrecisionHelperFactory.CreatePrecisionHelper(
         self._precision)
 
-    fraction_of_second = precision_helper.CopyMicrosecondsToFractionOfSecond(
-        microseconds)
+    fraction_of_second = precision_helper.CopyNanosecondsToFractionOfSecond(
+        nanoseconds)
 
     self._normalized_timestamp = None
     self._number_of_seconds = self._GetNumberOfSecondsFromElements(
@@ -985,8 +985,8 @@ def CopyFromDatetime(self, datetime_object):
     precision_helper = precisions.PrecisionHelperFactory.CreatePrecisionHelper(
         self._precision)
 
-    fraction_of_second = precision_helper.CopyMicrosecondsToFractionOfSecond(
-        datetime_object.microsecond)
+    fraction_of_second = precision_helper.CopyNanosecondsToFractionOfSecond(
+        datetime_object.microsecond * definitions.NANOSECONDS_PER_MICROSECOND)
     self.fraction_of_second = fraction_of_second
 
   def CopyFromStringTuple(self, time_elements_tuple):
diff --git a/dfdatetime/uuid_time.py b/dfdatetime/uuid_time.py
index 73940f4..0c7eb17 100644
--- a/dfdatetime/uuid_time.py
+++ b/dfdatetime/uuid_time.py
@@ -89,7 +89,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
@@ -104,17 +104,19 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
     if year < 1582:
       raise ValueError('Year value not supported.')
 
+    nanoseconds, _ = divmod(nanoseconds, 100)
+
     timestamp = self._GetNumberOfSecondsFromElements(
         year, month, day_of_month, hours, minutes, seconds)
     timestamp += self._UUID_TO_POSIX_BASE
-    timestamp *= definitions.MICROSECONDS_PER_SECOND
-    timestamp += date_time_values.get('microseconds', 0)
-    timestamp *= self._100_NANOSECONDS_PER_MICROSECOND
+    timestamp *= self._100_NANOSECONDS_PER_SECOND
+    timestamp += nanoseconds
 
     self._normalized_timestamp = None
     self._timestamp = timestamp
diff --git a/dfdatetime/webkit_time.py b/dfdatetime/webkit_time.py
index 350452d..ac37a82 100644
--- a/dfdatetime/webkit_time.py
+++ b/dfdatetime/webkit_time.py
@@ -80,7 +80,7 @@ def CopyFromDateTimeString(self, time_string):
           YYYY-MM-DD hh:mm:ss.######[+-]##:##
 
           Where # are numeric digits ranging from 0 to 9 and the seconds
-          fraction can be either 3 or 6 digits. The time of day, seconds
+          fraction can be either 3, 6 or 9 digits. The time of day, seconds
           fraction and time zone offset are optional. The default time zone
           is UTC.
 
@@ -95,13 +95,17 @@ def CopyFromDateTimeString(self, time_string):
     hours = date_time_values.get('hours', 0)
     minutes = date_time_values.get('minutes', 0)
     seconds = date_time_values.get('seconds', 0)
+    nanoseconds = date_time_values.get('nanoseconds', 0)
     time_zone_offset = date_time_values.get('time_zone_offset', 0)
 
+    microseconds, _ = divmod(
+        nanoseconds, definitions.NANOSECONDS_PER_MICROSECOND)
+
     timestamp = self._GetNumberOfSecondsFromElements(
         year, month, day_of_month, hours, minutes, seconds)
     timestamp += self._WEBKIT_TO_POSIX_BASE
     timestamp *= definitions.MICROSECONDS_PER_SECOND
-    timestamp += date_time_values.get('microseconds', 0)
+    timestamp += microseconds
 
     self._normalized_timestamp = None
     self._timestamp = timestamp
diff --git a/setup.cfg b/setup.cfg
index 6e35c01..ea154a8 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -1,6 +1,6 @@
 [metadata]
 name = dfdatetime
-version = 20231205
+version = 20231210
 description = Digital Forensics date and time (dfDateTime).
 long_description = dfDateTime, or Digital Forensics date and time, provides date and time objects to preserve accuracy and precision.
 long_description_content_type = text/plain
diff --git a/tests/interface.py b/tests/interface.py
index aab2ace..1af29c4 100644
--- a/tests/interface.py
+++ b/tests/interface.py
@@ -191,14 +191,14 @@ def testCopyDateTimeFromString(self):
 
     expected_date_dict = {
         'year': 2010, 'month': 8, 'day_of_month': 12,
-        'hours': 21, 'minutes': 6, 'seconds': 31, 'microseconds': 546875}
+        'hours': 21, 'minutes': 6, 'seconds': 31, 'nanoseconds': 546875000}
     date_dict = date_time_values._CopyDateTimeFromString(
         '2010-08-12 21:06:31.546875')
     self.assertEqual(date_dict, expected_date_dict)
 
     expected_date_dict = {
         'year': 2010, 'month': 8, 'day_of_month': 12,
-        'hours': 21, 'minutes': 6, 'seconds': 31, 'microseconds': 546875,
+        'hours': 21, 'minutes': 6, 'seconds': 31, 'nanoseconds': 546875000,
         'time_zone_offset': -60}
     date_dict = date_time_values._CopyDateTimeFromString(
         '2010-08-12 21:06:31.546875-01:00')
@@ -206,12 +206,20 @@ def testCopyDateTimeFromString(self):
 
     expected_date_dict = {
         'year': 2010, 'month': 8, 'day_of_month': 12,
-        'hours': 21, 'minutes': 6, 'seconds': 31, 'microseconds': 546875,
+        'hours': 21, 'minutes': 6, 'seconds': 31, 'nanoseconds': 546875000,
         'time_zone_offset': 60}
     date_dict = date_time_values._CopyDateTimeFromString(
         '2010-08-12 21:06:31.546875+01:00')
     self.assertEqual(date_dict, expected_date_dict)
 
+    expected_date_dict = {
+        'year': 2010, 'month': 8, 'day_of_month': 12,
+        'hours': 21, 'minutes': 6, 'seconds': 31, 'nanoseconds': 546875333,
+        'time_zone_offset': 60}
+    date_dict = date_time_values._CopyDateTimeFromString(
+        '2010-08-12 21:06:31.546875333+01:00')
+    self.assertEqual(date_dict, expected_date_dict)
+
     with self.assertRaises(ValueError):
       date_time_values._CopyDateTimeFromString('')
 
@@ -235,19 +243,19 @@ def testCopyTimeFromString(self):
     time_tuple = date_time_values._CopyTimeFromString('20:23:56+05:30')
     self.assertEqual(time_tuple, expected_time_tuple)
 
-    expected_time_tuple = (20, 23, 56, 327000, None)
+    expected_time_tuple = (20, 23, 56, 327000000, None)
     time_tuple = date_time_values._CopyTimeFromString('20:23:56.327')
     self.assertEqual(time_tuple, expected_time_tuple)
 
-    expected_time_tuple = (20, 23, 56, 327000, 60)
+    expected_time_tuple = (20, 23, 56, 327000000, 60)
     time_tuple = date_time_values._CopyTimeFromString('20:23:56.327+01:00')
     self.assertEqual(time_tuple, expected_time_tuple)
 
-    expected_time_tuple = (20, 23, 56, 327124, None)
+    expected_time_tuple = (20, 23, 56, 327124000, None)
     time_tuple = date_time_values._CopyTimeFromString('20:23:56.327124')
     self.assertEqual(time_tuple, expected_time_tuple)
 
-    expected_time_tuple = (20, 23, 56, 327124, -300)
+    expected_time_tuple = (20, 23, 56, 327124000, -300)
     time_tuple = date_time_values._CopyTimeFromString('20:23:56.327124-05:00')
     self.assertEqual(time_tuple, expected_time_tuple)
 
diff --git a/tests/precisions.py b/tests/precisions.py
index b74238c..fcd558a 100644
--- a/tests/precisions.py
+++ b/tests/precisions.py
@@ -12,12 +12,12 @@
 class DateTimePrecisionHelperTest(unittest.TestCase):
   """Tests for the date time precision helper interface."""
 
-  def testCopyMicrosecondsToFractionOfSecond(self):
-    """Tests the CopyMicrosecondsToFractionOfSecond function."""
+  def testCopyNanosecondsToFractionOfSecond(self):
+    """Tests the CopyNanosecondsToFractionOfSecond function."""
     precision_helper = precisions.DateTimePrecisionHelper
 
     with self.assertRaises(NotImplementedError):
-      precision_helper.CopyMicrosecondsToFractionOfSecond(0)
+      precision_helper.CopyNanosecondsToFractionOfSecond(0)
 
   def testCopyToDateTimeString(self):
     """Tests the CopyToDateTimeString function."""
@@ -30,19 +30,19 @@ def testCopyToDateTimeString(self):
 class SecondsPrecisionHelperTest(unittest.TestCase):
   """Tests for the seconds precision helper."""
 
-  def testCopyMicrosecondsToFractionOfSecond(self):
-    """Tests the CopyMicrosecondsToFractionOfSecond function."""
+  def testCopyNanosecondsToFractionOfSecond(self):
+    """Tests the CopyNanosecondsToFractionOfSecond function."""
     precision_helper = precisions.SecondsPrecisionHelper
 
-    fraction_of_second = precision_helper.CopyMicrosecondsToFractionOfSecond(
+    fraction_of_second = precision_helper.CopyNanosecondsToFractionOfSecond(
         123456)
     self.assertEqual(fraction_of_second, 0.0)
 
     with self.assertRaises(ValueError):
-      precision_helper.CopyMicrosecondsToFractionOfSecond(-1)
+      precision_helper.CopyNanosecondsToFractionOfSecond(-1)
 
     with self.assertRaises(ValueError):
-      precision_helper.CopyMicrosecondsToFractionOfSecond(1000000)
+      precision_helper.CopyNanosecondsToFractionOfSecond(1000000000)
 
   def testCopyToDateTimeString(self):
     """Tests the CopyToDateTimeString function."""
@@ -59,19 +59,19 @@ def testCopyToDateTimeString(self):
 class MillisecondsPrecisionHelperTest(unittest.TestCase):
   """Tests for the milliseconds precision helper."""
 
-  def testCopyMicrosecondsToFractionOfSecond(self):
-    """Tests the CopyMicrosecondsToFractionOfSecond function."""
+  def testCopyNanosecondsToFractionOfSecond(self):
+    """Tests the CopyNanosecondsToFractionOfSecond function."""
     precision_helper = precisions.MillisecondsPrecisionHelper
 
-    fraction_of_second = precision_helper.CopyMicrosecondsToFractionOfSecond(
-        123456)
+    fraction_of_second = precision_helper.CopyNanosecondsToFractionOfSecond(
+        123456789)
     self.assertEqual(fraction_of_second, decimal.Decimal('0.123'))
 
     with self.assertRaises(ValueError):
-      precision_helper.CopyMicrosecondsToFractionOfSecond(-1)
+      precision_helper.CopyNanosecondsToFractionOfSecond(-1)
 
     with self.assertRaises(ValueError):
-      precision_helper.CopyMicrosecondsToFractionOfSecond(1000000)
+      precision_helper.CopyNanosecondsToFractionOfSecond(1000000000)
 
   def testCopyToDateTimeString(self):
     """Tests the CopyToDateTimeString function."""
@@ -86,21 +86,21 @@ def testCopyToDateTimeString(self):
 
 
 class MicrosecondsPrecisionHelperTest(unittest.TestCase):
-  """Tests for the milliseconds precision helper."""
+  """Tests for the microseconds precision helper."""
 
-  def testCopyMicrosecondsToFractionOfSecond(self):
-    """Tests the CopyMicrosecondsToFractionOfSecond function."""
+  def testCopyNanosecondsToFractionOfSecond(self):
+    """Tests the CopyNanosecondsToFractionOfSecond function."""
     precision_helper = precisions.MicrosecondsPrecisionHelper
 
-    fraction_of_second = precision_helper.CopyMicrosecondsToFractionOfSecond(
-        123456)
+    fraction_of_second = precision_helper.CopyNanosecondsToFractionOfSecond(
+        123456789)
     self.assertEqual(fraction_of_second, decimal.Decimal('0.123456'))
 
     with self.assertRaises(ValueError):
-      precision_helper.CopyMicrosecondsToFractionOfSecond(-1)
+      precision_helper.CopyNanosecondsToFractionOfSecond(-1)
 
     with self.assertRaises(ValueError):
-      precision_helper.CopyMicrosecondsToFractionOfSecond(1000000)
+      precision_helper.CopyNanosecondsToFractionOfSecond(1000000000)
 
   def testCopyToDateTimeString(self):
     """Tests the CopyToDateTimeString function."""
@@ -114,6 +114,36 @@ def testCopyToDateTimeString(self):
       precision_helper.CopyToDateTimeString((2018, 1, 2, 19, 45, 12), 4.123456)
 
 
+class NanosecondsPrecisionHelperTest(unittest.TestCase):
+  """Tests for the nanoseconds precision helper."""
+
+  def testCopyNanosecondsToFractionOfSecond(self):
+    """Tests the CopyNanosecondsToFractionOfSecond function."""
+    precision_helper = precisions.NanosecondsPrecisionHelper
+
+    fraction_of_second = precision_helper.CopyNanosecondsToFractionOfSecond(
+        123456789)
+    self.assertEqual(fraction_of_second, decimal.Decimal('0.123456789'))
+
+    with self.assertRaises(ValueError):
+      precision_helper.CopyNanosecondsToFractionOfSecond(-1)
+
+    with self.assertRaises(ValueError):
+      precision_helper.CopyNanosecondsToFractionOfSecond(1000000000)
+
+  def testCopyToDateTimeString(self):
+    """Tests the CopyToDateTimeString function."""
+    precision_helper = precisions.NanosecondsPrecisionHelper
+
+    date_time_string = precision_helper.CopyToDateTimeString(
+        (2018, 1, 2, 19, 45, 12), 0.123456789)
+    self.assertEqual(date_time_string, '2018-01-02 19:45:12.123456789')
+
+    with self.assertRaises(ValueError):
+      precision_helper.CopyToDateTimeString(
+          (2018, 1, 2, 19, 45, 12), 4.123456789)
+
+
 class PrecisionHelperFactoryTest(unittest.TestCase):
   """Tests for the date time precision helper factory."""
 
diff --git a/tests/time_elements.py b/tests/time_elements.py
index e043501..092e986 100644
--- a/tests/time_elements.py
+++ b/tests/time_elements.py
@@ -103,14 +103,14 @@ def testCopyDateTimeFromStringISO8601(self):
 
     expected_date_dict = {
         'year': 2010, 'month': 8, 'day_of_month': 12,
-        'hours': 21, 'minutes': 6, 'seconds': 31, 'microseconds': 546875}
+        'hours': 21, 'minutes': 6, 'seconds': 31, 'nanoseconds': 546875000}
     date_dict = time_elements_object._CopyDateTimeFromStringISO8601(
         '2010-08-12T21:06:31.546875')
     self.assertEqual(date_dict, expected_date_dict)
 
     expected_date_dict = {
         'year': 2010, 'month': 8, 'day_of_month': 12,
-        'hours': 21, 'minutes': 6, 'seconds': 31, 'microseconds': 546875,
+        'hours': 21, 'minutes': 6, 'seconds': 31, 'nanoseconds': 546875000,
         'time_zone_offset': -60}
     date_dict = time_elements_object._CopyDateTimeFromStringISO8601(
         '2010-08-12T21:06:31.546875-01:00')
@@ -118,12 +118,20 @@ def testCopyDateTimeFromStringISO8601(self):
 
     expected_date_dict = {
         'year': 2010, 'month': 8, 'day_of_month': 12,
-        'hours': 21, 'minutes': 6, 'seconds': 31, 'microseconds': 546875,
+        'hours': 21, 'minutes': 6, 'seconds': 31, 'nanoseconds': 546875000,
         'time_zone_offset': 60}
     date_dict = time_elements_object._CopyDateTimeFromStringISO8601(
         '2010-08-12T21:06:31.546875+01:00')
     self.assertEqual(date_dict, expected_date_dict)
 
+    expected_date_dict = {
+        'year': 2010, 'month': 8, 'day_of_month': 12,
+        'hours': 21, 'minutes': 6, 'seconds': 31, 'nanoseconds': 546875333,
+        'time_zone_offset': 60}
+    date_dict = time_elements_object._CopyDateTimeFromStringISO8601(
+        '2010-08-12T21:06:31.546875333+01:00')
+    self.assertEqual(date_dict, expected_date_dict)
+
     with self.assertRaises(ValueError):
       time_elements_object._CopyDateTimeFromStringISO8601('')
 
@@ -309,16 +317,16 @@ def testCopyTimeFromStringISO8601(self):
         '20:23:56+05:30')
     self.assertEqual(time_tuple, expected_time_tuple)
 
-    expected_time_tuple = (20, 23, 56, 327000, None)
+    expected_time_tuple = (20, 23, 56, 327000000, None)
     time_tuple = time_elements_object._CopyTimeFromStringISO8601('20:23:56.327')
     self.assertEqual(time_tuple, expected_time_tuple)
 
-    expected_time_tuple = (20, 23, 56, 327000, 60)
+    expected_time_tuple = (20, 23, 56, 327000000, 60)
     time_tuple = time_elements_object._CopyTimeFromStringISO8601(
         '20:23:56.327+01:00')
     self.assertEqual(time_tuple, expected_time_tuple)
 
-    expected_time_tuple = (20, 23, 56, 327124, None)
+    expected_time_tuple = (20, 23, 56, 327124000, None)
     time_tuple = time_elements_object._CopyTimeFromStringISO8601(
         '20:23:56.327124')
     self.assertEqual(time_tuple, expected_time_tuple)
@@ -332,7 +340,7 @@ def testCopyTimeFromStringISO8601(self):
         '08:04:32+00:00')
     self.assertEqual(time_tuple, expected_time_tuple)
 
-    expected_time_tuple = (20, 23, 56, 327124, -300)
+    expected_time_tuple = (20, 23, 56, 327124000, -300)
     time_tuple = time_elements_object._CopyTimeFromStringISO8601(
         '20:23:56.327124-05:00')
     self.assertEqual(time_tuple, expected_time_tuple)