diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
index 4c74d5a254a93..87a03dcdfa218 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Unix.cs
@@ -271,59 +271,13 @@ private static TimeZoneInfoResult TryGetTimeZoneFromLocalMachine(string id, out
///
/// Helper function for retrieving a TimeZoneInfo object by time_zone_name.
- /// This function wraps the logic necessary to keep the private
- /// SystemTimeZones cache in working order
///
- /// This function will either return a valid TimeZoneInfo instance or
- /// it will throw 'InvalidTimeZoneException' / 'TimeZoneNotFoundException'.
+ /// This function may return null.
+ ///
+ /// assumes cachedData lock is taken
///
- public static TimeZoneInfo FindSystemTimeZoneById(string id)
- {
- // Special case for Utc as it will not exist in the dictionary with the rest
- // of the system time zones. There is no need to do this check for Local.Id
- // since Local is a real time zone that exists in the dictionary cache
- if (string.Equals(id, UtcId, StringComparison.OrdinalIgnoreCase))
- {
- return Utc;
- }
-
- ArgumentNullException.ThrowIfNull(id);
- if (id.Length == 0 || id.Contains('\0'))
- {
- throw new TimeZoneNotFoundException(SR.Format(SR.TimeZoneNotFound_MissingData, id));
- }
-
- TimeZoneInfo? value;
- Exception? e;
-
- TimeZoneInfoResult result;
-
- CachedData cachedData = s_cachedData;
-
- lock (cachedData)
- {
- result = TryGetTimeZone(id, false, out value, out e, cachedData, alwaysFallbackToLocalMachine: true);
- }
-
- if (result == TimeZoneInfoResult.Success)
- {
- return value!;
- }
- else if (result == TimeZoneInfoResult.InvalidTimeZoneException)
- {
- Debug.Assert(e is InvalidTimeZoneException,
- "TryGetTimeZone must create an InvalidTimeZoneException when it returns TimeZoneInfoResult.InvalidTimeZoneException");
- throw e;
- }
- else if (result == TimeZoneInfoResult.SecurityException)
- {
- throw new SecurityException(SR.Format(SR.Security_CannotReadFileData, id), e);
- }
- else
- {
- throw new TimeZoneNotFoundException(SR.Format(SR.TimeZoneNotFound_MissingData, id), e);
- }
- }
+ private static TimeZoneInfoResult TryGetTimeZone(string id, out TimeZoneInfo? timeZone, out Exception? e, CachedData cachedData)
+ => TryGetTimeZone(id, false, out timeZone, out e, cachedData, alwaysFallbackToLocalMachine: true);
// DateTime.Now fast path that avoids allocating an historically accurate TimeZoneInfo.Local and just creates a 1-year (current year) accurate time zone
internal static TimeSpan GetDateTimeNowUtcOffsetFromUtc(DateTime time, out bool isAmbiguousLocalDst)
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Win32.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Win32.cs
index c748b9afa609a..3344e9ef82b77 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Win32.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.Win32.cs
@@ -32,7 +32,6 @@ public sealed partial class TimeZoneInfo
private const string FirstEntryValue = "FirstEntry";
private const string LastEntryValue = "LastEntry";
- private const int MaxKeyLength = 255;
private const string InvariantUtcStandardDisplayName = "Coordinated Universal Time";
private sealed partial class CachedData
@@ -314,56 +313,13 @@ private static TimeZoneInfo GetLocalTimeZoneFromWin32Data(in TIME_ZONE_INFORMATI
///
/// Helper function for retrieving a TimeZoneInfo object by time_zone_name.
- /// This function wraps the logic necessary to keep the private
- /// SystemTimeZones cache in working order
///
- /// This function will either return a valid TimeZoneInfo instance or
- /// it will throw 'InvalidTimeZoneException' / 'TimeZoneNotFoundException'.
+ /// This function may return null.
+ ///
+ /// assumes cachedData lock is taken
///
- public static TimeZoneInfo FindSystemTimeZoneById(string id)
- {
- ArgumentNullException.ThrowIfNull(id);
-
- // Special case for Utc to avoid having TryGetTimeZone creating a new Utc object
- if (string.Equals(id, UtcId, StringComparison.OrdinalIgnoreCase))
- {
- return Utc;
- }
-
- if (id.Length == 0 || id.Length > MaxKeyLength || id.Contains('\0'))
- {
- throw new TimeZoneNotFoundException(SR.Format(SR.TimeZoneNotFound_MissingData, id));
- }
-
- TimeZoneInfo? value;
- Exception? e;
-
- TimeZoneInfoResult result;
-
- CachedData cachedData = s_cachedData;
-
- lock (cachedData)
- {
- result = TryGetTimeZone(id, false, out value, out e, cachedData);
- }
-
- if (result == TimeZoneInfoResult.Success)
- {
- return value!;
- }
- else if (result == TimeZoneInfoResult.InvalidTimeZoneException)
- {
- throw new InvalidTimeZoneException(SR.Format(SR.InvalidTimeZone_InvalidRegistryData, id), e);
- }
- else if (result == TimeZoneInfoResult.SecurityException)
- {
- throw new SecurityException(SR.Format(SR.Security_CannotReadRegistryData, id), e);
- }
- else
- {
- throw new TimeZoneNotFoundException(SR.Format(SR.TimeZoneNotFound_MissingData, id), e);
- }
- }
+ private static TimeZoneInfoResult TryGetTimeZone(string id, out TimeZoneInfo? timeZone, out Exception? e, CachedData cachedData)
+ => TryGetTimeZone(id, false, out timeZone, out e, cachedData);
// DateTime.Now fast path that avoids allocating an historically accurate TimeZoneInfo.Local and just creates a 1-year (current year) accurate time zone
internal static TimeSpan GetDateTimeNowUtcOffsetFromUtc(DateTime time, out bool isAmbiguousLocalDst)
diff --git a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.cs b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.cs
index 2d354edaa1620..97c6d0a10f7ae 100644
--- a/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.cs
+++ b/src/libraries/System.Private.CoreLib/src/System/TimeZoneInfo.cs
@@ -8,6 +8,7 @@
using System.Globalization;
using System.Runtime.CompilerServices;
using System.Runtime.Serialization;
+using System.Security;
using System.Threading;
namespace System
@@ -40,6 +41,8 @@ private enum TimeZoneInfoResult
SecurityException = 3
}
+ private const int MaxKeyLength = 255;
+
private readonly string _id;
private readonly string? _displayName;
private readonly string? _standardDisplayName;
@@ -556,6 +559,90 @@ public static DateTimeOffset ConvertTimeBySystemTimeZoneId(DateTimeOffset dateTi
public static DateTime ConvertTimeBySystemTimeZoneId(DateTime dateTime, string destinationTimeZoneId) =>
ConvertTime(dateTime, FindSystemTimeZoneById(destinationTimeZoneId));
+ ///
+ /// Helper function for retrieving a object by time zone name.
+ /// This function wraps the logic necessary to keep the private
+ /// SystemTimeZones cache in working order.
+ ///
+ /// This function will either return a valid instance or
+ /// it will throw / /
+ ///
+ ///
+ /// Time zone name.
+ /// Valid instance.
+ public static TimeZoneInfo FindSystemTimeZoneById(string id)
+ {
+ TimeZoneInfo? value;
+ Exception? e;
+
+ TimeZoneInfoResult result = TryFindSystemTimeZoneById(id, out value, out e);
+ switch (result)
+ {
+ case TimeZoneInfoResult.Success:
+ return value!;
+ case TimeZoneInfoResult.InvalidTimeZoneException:
+ Debug.Assert(e is InvalidTimeZoneException,
+ "TryGetTimeZone must create an InvalidTimeZoneException when it returns TimeZoneInfoResult.InvalidTimeZoneException");
+ throw e;
+ case TimeZoneInfoResult.SecurityException:
+ throw new SecurityException(SR.Format(SR.Security_CannotReadFileData, id), e);
+ default:
+ throw new TimeZoneNotFoundException(SR.Format(SR.TimeZoneNotFound_MissingData, id), e);
+ }
+ }
+
+ ///
+ /// Helper function for retrieving a object by time zone name.
+ /// This function wraps the logic necessary to keep the private
+ /// SystemTimeZones cache in working order.
+ ///
+ /// This function will either return true and a valid
+ /// instance or return false and null.
+ ///
+ /// Time zone name.
+ /// A valid retrieved or null.
+ /// true if the object was successfully retrieved, false otherwise.
+ public static bool TryFindSystemTimeZoneById(string id, [NotNullWhenAttribute(true)] out TimeZoneInfo? timeZoneInfo)
+ => TryFindSystemTimeZoneById(id, out timeZoneInfo, out _) == TimeZoneInfoResult.Success;
+
+ ///
+ /// Helper function for retrieving a TimeZoneInfo object by time_zone_name.
+ /// This function wraps the logic necessary to keep the private
+ /// SystemTimeZones cache in working order.
+ ///
+ /// This function will either return:
+ /// TimeZoneInfoResult.Success and a valid instance and null Exception or
+ /// TimeZoneInfoResult.TimeZoneNotFoundException and null and Exception (can be null) or
+ /// other TimeZoneInfoResult and null and valid Exception.
+ ///
+ private static TimeZoneInfoResult TryFindSystemTimeZoneById(string id, out TimeZoneInfo? timeZone, out Exception? e)
+ {
+ // Special case for Utc as it will not exist in the dictionary with the rest
+ // of the system time zones. There is no need to do this check for Local.Id
+ // since Local is a real time zone that exists in the dictionary cache
+ if (string.Equals(id, UtcId, StringComparison.OrdinalIgnoreCase))
+ {
+ timeZone = Utc;
+ e = default;
+ return TimeZoneInfoResult.Success;
+ }
+
+ ArgumentNullException.ThrowIfNull(id);
+ if (id.Length == 0 || id.Length > MaxKeyLength || id.Contains('\0'))
+ {
+ timeZone = default;
+ e = default;
+ return TimeZoneInfoResult.TimeZoneNotFoundException;
+ }
+
+ CachedData cachedData = s_cachedData;
+
+ lock (cachedData)
+ {
+ return TryGetTimeZone(id, out timeZone, out e, cachedData);
+ }
+ }
+
///
/// Converts the value of a DateTime object from sourceTimeZone to destinationTimeZone.
///
diff --git a/src/libraries/System.Runtime/ref/System.Runtime.cs b/src/libraries/System.Runtime/ref/System.Runtime.cs
index e5421cf35e93a..9de97af5b7c50 100644
--- a/src/libraries/System.Runtime/ref/System.Runtime.cs
+++ b/src/libraries/System.Runtime/ref/System.Runtime.cs
@@ -5610,6 +5610,7 @@ public static void ClearCachedData() { }
public override bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] object? obj) { throw null; }
public bool Equals([System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] System.TimeZoneInfo? other) { throw null; }
public static System.TimeZoneInfo FindSystemTimeZoneById(string id) { throw null; }
+ public static bool TryFindSystemTimeZoneById(string id, [System.Diagnostics.CodeAnalysis.NotNullWhenAttribute(true)] out System.TimeZoneInfo? timeZoneInfo) { throw null; }
public static System.TimeZoneInfo FromSerializedString(string source) { throw null; }
public System.TimeZoneInfo.AdjustmentRule[] GetAdjustmentRules() { throw null; }
public System.TimeSpan[] GetAmbiguousTimeOffsets(System.DateTime dateTime) { throw null; }
diff --git a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
index 46dfb23a45877..18c033afd2ade 100644
--- a/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
+++ b/src/libraries/System.Runtime/tests/System/TimeZoneInfoTests.cs
@@ -166,11 +166,13 @@ public static void LibyaTimeZone()
try
{
tripoli = TimeZoneInfo.FindSystemTimeZoneById(s_strLibya);
+ Assert.True(TimeZoneInfo.TryFindSystemTimeZoneById(s_strLibya, out _));
}
catch (Exception /* TimeZoneNotFoundException in netstandard1.7 test*/ )
{
// Libya time zone not found
Console.WriteLine("Warning: Libya time zone is not exist in this machine");
+ Assert.False(TimeZoneInfo.TryFindSystemTimeZoneById(s_strLibya, out _));
return;
}
@@ -189,6 +191,7 @@ public static void TestYukonTZ()
try
{
TimeZoneInfo yukon = TimeZoneInfo.FindSystemTimeZoneById("Yukon Standard Time");
+ Assert.True(TimeZoneInfo.TryFindSystemTimeZoneById("Yukon Standard Time", out _));
// First, ensure we have the updated data
TimeZoneInfo.AdjustmentRule[] rules = yukon.GetAdjustmentRules();
@@ -214,6 +217,8 @@ public static void TestYukonTZ()
catch (TimeZoneNotFoundException)
{
// Some Windows versions don't carry the complete TZ data. Ignore the tests on such versions.
+ Assert.False(TimeZoneInfo.TryFindSystemTimeZoneById("Yukon Standard Time", out _));
+ return;
}
}
@@ -221,6 +226,7 @@ public static void TestYukonTZ()
public static void RussianTimeZone()
{
TimeZoneInfo tz = TimeZoneInfo.FindSystemTimeZoneById(s_strRussian);
+ Assert.True(TimeZoneInfo.TryFindSystemTimeZoneById(s_strRussian, out _));
var inputUtcDate = new DateTime(2013, 6, 1, 0, 0, 0, DateTimeKind.Utc);
DateTime russiaTime = TimeZoneInfo.ConvertTime(inputUtcDate, tz);
@@ -2060,6 +2066,15 @@ public static void ClearCachedData()
{
TimeZoneInfo.ConvertTime(DateTime.Now, local, cst);
});
+
+ Assert.True(TimeZoneInfo.TryFindSystemTimeZoneById(s_strSydney, out cst));
+ local = TimeZoneInfo.Local;
+
+ TimeZoneInfo.ClearCachedData();
+ Assert.ThrowsAny(() =>
+ {
+ TimeZoneInfo.ConvertTime(DateTime.Now, local, cst);
+ });
}
[Fact]
@@ -2721,6 +2736,9 @@ public static void EnsureUtcObjectSingleton()
TimeZoneInfo utcObject = TimeZoneInfo.GetSystemTimeZones().Single(x => x.Id.Equals("UTC", StringComparison.OrdinalIgnoreCase));
Assert.True(ReferenceEquals(utcObject, TimeZoneInfo.Utc));
Assert.True(ReferenceEquals(TimeZoneInfo.FindSystemTimeZoneById("UTC"), TimeZoneInfo.Utc));
+
+ Assert.True(TimeZoneInfo.TryFindSystemTimeZoneById("UTC", out TimeZoneInfo tz));
+ Assert.True(ReferenceEquals(tz, TimeZoneInfo.Utc));
}
[ConditionalTheory(typeof(PlatformDetection), nameof(PlatformDetection.IsNotBrowser))]
@@ -2748,11 +2766,20 @@ public static void UsingAlternativeTimeZoneIdsTest(string windowsId, string iana
Assert.Equal(tzi1.BaseUtcOffset, tzi2.BaseUtcOffset);
Assert.NotEqual(tzi1.Id, tzi2.Id);
+
+ Assert.True(TimeZoneInfo.TryFindSystemTimeZoneById(ianaId, out tzi1));
+ Assert.True(TimeZoneInfo.TryFindSystemTimeZoneById(windowsId, out tzi2));
+
+ Assert.Equal(tzi1.BaseUtcOffset, tzi2.BaseUtcOffset);
+ Assert.NotEqual(tzi1.Id, tzi2.Id);
}
else
{
Assert.Throws(() => TimeZoneInfo.FindSystemTimeZoneById(s_isWindows ? ianaId : windowsId));
TimeZoneInfo tzi = TimeZoneInfo.FindSystemTimeZoneById(s_isWindows ? windowsId : ianaId);
+
+ Assert.False(TimeZoneInfo.TryFindSystemTimeZoneById(s_isWindows ? ianaId : windowsId, out _));
+ Assert.True(TimeZoneInfo.TryFindSystemTimeZoneById(s_isWindows ? windowsId : ianaId, out _));
}
}
@@ -2800,6 +2827,8 @@ public static void UnsupportedImplicitConversionTest()
string nonNativeTzName = s_isWindows ? "America/Los_Angeles" : "Pacific Standard Time";
Assert.Throws(() => TimeZoneInfo.FindSystemTimeZoneById(nonNativeTzName));
+
+ Assert.False(TimeZoneInfo.TryFindSystemTimeZoneById(nonNativeTzName, out _));
}
[ConditionalTheory(nameof(SupportIanaNamesConversion))]
@@ -2948,6 +2977,23 @@ public static void ChangeLocalTimeZone(string id)
TimeZoneInfo.ClearCachedData();
Environment.SetEnvironmentVariable("TZ", originalTZ);
}
+
+ try
+ {
+ TimeZoneInfo.ClearCachedData();
+ Environment.SetEnvironmentVariable("TZ", id);
+
+ TimeZoneInfo localtz = TimeZoneInfo.Local;
+ Assert.True(TimeZoneInfo.TryFindSystemTimeZoneById(id, out TimeZoneInfo tz));
+
+ Assert.Equal(tz.StandardName, localtz.StandardName);
+ Assert.Equal(tz.DisplayName, localtz.DisplayName);
+ }
+ finally
+ {
+ TimeZoneInfo.ClearCachedData();
+ Environment.SetEnvironmentVariable("TZ", originalTZ);
+ }
}
[Fact]