diff --git a/src/datetime/tests.rs b/src/datetime/tests.rs
index c17e6320fd..cab6059b0b 100644
--- a/src/datetime/tests.rs
+++ b/src/datetime/tests.rs
@@ -1042,17 +1042,18 @@ fn test_datetime_parse_from_str() {
     // %:z
     //
     assert_eq!(parse("Aug 09 2013 23:54:35  -09:00", "%b %d %Y %H:%M:%S  %:z"), Ok(dt));
-    assert_eq!(parse("Aug 09 2013 23:54:35 -0900", "%b %d %Y %H:%M:%S %:z"), Ok(dt));
+    assert!(parse("Aug 09 2013 23:54:35 -0900", "%b %d %Y %H:%M:%S %:z").is_err());
     assert!(parse("Aug 09 2013 23:54:35 -09 00", "%b %d %Y %H:%M:%S %:z").is_err());
     assert!(parse("Aug 09 2013 23:54:35 -09 : 00", "%b %d %Y %H:%M:%S %:z").is_err());
-    assert!(parse("Aug 09 2013 23:54:35 -09 : 00:", "%b %d %Y %H:%M:%S %:z:").is_err());
+    assert!(parse("Aug 09 2013 23:54:35 -09:0", "%b %d %Y %H:%M:%S %:z:").is_err());
+    assert!(parse("Aug 09 2013 23:54:35 -09:", "%b %d %Y %H:%M:%S %:z:").is_err());
     // wrong timezone data
     assert!(parse("Aug 09 2013 23:54:35 -09", "%b %d %Y %H:%M:%S %:z").is_err());
+    assert!(parse("Aug 09 2013 23:54:35 -090000", "%b %d %Y %H:%M:%S %:z").is_err());
+    assert!(parse("Aug 09 2013 23:54:35 -09:00:00", "%b %d %Y %H:%M:%S %:z").is_err());
+    // timezone data has too many colons
     assert!(parse("Aug 09 2013 23:54:35 -09::00", "%b %d %Y %H:%M:%S %:z").is_err());
-    // timezone data hs too many colons
     assert!(parse("Aug 09 2013 23:54:35 -09:00:", "%b %d %Y %H:%M:%S %:z").is_err());
-    // timezone data hs too many colons
-    assert!(parse("Aug 09 2013 23:54:35 -09:00::", "%b %d %Y %H:%M:%S %:z").is_err());
     assert_eq!(parse("Aug 09 2013 23:54:35 -09:00::", "%b %d %Y %H:%M:%S %:z::"), Ok(dt));
 
     //
diff --git a/src/format/mod.rs b/src/format/mod.rs
index 912a9344cd..a98109d897 100644
--- a/src/format/mod.rs
+++ b/src/format/mod.rs
@@ -210,7 +210,6 @@ pub enum Fixed {
     TimezoneName,
     /// Offset from the local time to UTC (`+09:00` or `-0400` or `+00:00`).
     ///
-    /// In the parser, the colon may be omitted,
     /// The offset is limited from `-24:00` to `+24:00`,
     /// which is the same as [`FixedOffset`](../offset/struct.FixedOffset.html)'s range.
     TimezoneOffsetColon,
diff --git a/src/format/parse.rs b/src/format/parse.rs
index 58aa102d6f..a7e39bdf50 100644
--- a/src/format/parse.rs
+++ b/src/format/parse.rs
@@ -489,15 +489,24 @@ where
                         try_consume!(scan::timezone_name_skip(s));
                     }
 
-                    &TimezoneOffsetColon
-                    | &TimezoneOffset
-                    | &TimezoneOffsetColonZ
-                    | &TimezoneOffsetZ => {
+                    &TimezoneOffset | &TimezoneOffsetZ => {
                         s = scan::trim1(s);
                         let offset_format = UtcOffsetFormat {
                             precision: OffsetPrecision::Minutes,
                             colons: Colon::Maybe,
-                            allow_zulu: spec == &TimezoneOffsetColonZ || spec == &TimezoneOffsetZ,
+                            allow_zulu: spec == &TimezoneOffsetZ,
+                            padding: Pad::Zero,
+                        };
+                        let offset = try_consume!(scan::utc_offset(s, offset_format));
+                        parsed.set_offset(i64::from(offset)).map_err(|e| (s, e))?;
+                    }
+
+                    &TimezoneOffsetColon | &TimezoneOffsetColonZ => {
+                        s = scan::trim1(s);
+                        let offset_format = UtcOffsetFormat {
+                            precision: OffsetPrecision::Minutes,
+                            colons: Colon::Colon,
+                            allow_zulu: spec == &TimezoneOffsetColonZ,
                             padding: Pad::Zero,
                         };
                         let offset = try_consume!(scan::utc_offset(s, offset_format));
@@ -1101,13 +1110,11 @@ fn test_parse() {
     check!("12345678",     [fix!(TimezoneOffsetColon)]; INVALID);
     check!("+1",           [fix!(TimezoneOffsetColon)]; TOO_SHORT);
     check!("+12",          [fix!(TimezoneOffsetColon)]; TOO_SHORT);
-    check!("+123",         [fix!(TimezoneOffsetColon)]; TOO_SHORT);
-    check!("+1234",        [fix!(TimezoneOffsetColon)]; offset: 45_240);
-    check!("-1234",        [fix!(TimezoneOffsetColon)]; offset: -45_240);
-    check!("+12345",       [fix!(TimezoneOffsetColon)]; TOO_LONG);
-    check!("+123456",      [fix!(TimezoneOffsetColon)]; TOO_LONG);
-    check!("+1234567",     [fix!(TimezoneOffsetColon)]; TOO_LONG);
-    check!("+12345678",    [fix!(TimezoneOffsetColon)]; TOO_LONG);
+    check!("+123",         [fix!(TimezoneOffsetColon)]; INVALID);
+    check!("+1234",        [fix!(TimezoneOffsetColon)]; INVALID);
+    check!("-1234",        [fix!(TimezoneOffsetColon)]; INVALID);
+    check!("+12345",       [fix!(TimezoneOffsetColon)]; INVALID);
+    check!("+123456",      [fix!(TimezoneOffsetColon)]; INVALID);
     check!("1:",           [fix!(TimezoneOffsetColon)]; INVALID);
     check!("12:",          [fix!(TimezoneOffsetColon)]; INVALID);
     check!("12:3",         [fix!(TimezoneOffsetColon)]; INVALID);
@@ -1124,10 +1131,8 @@ fn test_parse() {
     check!("+12:34:5",     [fix!(TimezoneOffsetColon)]; TOO_LONG);
     check!("+12:34:56",    [fix!(TimezoneOffsetColon)]; TOO_LONG);
     check!("+12:34:56:",   [fix!(TimezoneOffsetColon)]; TOO_LONG);
-    check!("+12:34:56:7",  [fix!(TimezoneOffsetColon)]; TOO_LONG);
-    check!("+12:34:56:78", [fix!(TimezoneOffsetColon)]; TOO_LONG);
     check!("+12:3456",     [fix!(TimezoneOffsetColon)]; TOO_LONG);
-    check!("+1234:56",     [fix!(TimezoneOffsetColon)]; TOO_LONG);
+    check!("+1234:56",     [fix!(TimezoneOffsetColon)]; INVALID);
     check!("+12 34",       [fix!(TimezoneOffsetColon)]; INVALID);
     check!("+12: 34",      [fix!(TimezoneOffsetColon)]; INVALID);
     check!("+12 :34",      [fix!(TimezoneOffsetColon)]; INVALID);
@@ -1151,7 +1156,7 @@ fn test_parse() {
     check!("",             [fix!(TimezoneOffsetColon)]; TOO_SHORT);
     check!("+",            [fix!(TimezoneOffsetColon)]; TOO_SHORT);
     check!(":",            [fix!(TimezoneOffsetColon)]; INVALID);
-    check!("+12345",       [fix!(TimezoneOffsetColon), num!(Day)]; offset: 45_240, day: 5);
+    check!("+12345",       [fix!(TimezoneOffsetColon), num!(Day)]; INVALID);
     check!("+12:345",      [fix!(TimezoneOffsetColon), num!(Day)]; offset: 45_240, day: 5);
     check!("+12:34:",      [fix!(TimezoneOffsetColon), lit!(":")]; offset: 45_240);
     check!("Z",            [fix!(TimezoneOffsetColon)]; INVALID);