diff --git a/src/Parser/IsoParsers.php b/src/Parser/IsoParsers.php
index d4545dd..81f835a 100644
--- a/src/Parser/IsoParsers.php
+++ b/src/Parser/IsoParsers.php
@@ -206,7 +206,7 @@ public static function monthDay(): PatternParser
     }
 
     /**
-     * Returns a parser for a time-zone offset such as `Z` or `+01:00`.
+     * Returns a parser for a time-zone offset such as `Z`, `+01`, `+01:00`, `+01:00:00`.
      */
     public static function timeZoneOffset(): PatternParser
     {
@@ -220,8 +220,10 @@ public static function timeZoneOffset(): PatternParser
             ->startGroup()
             ->appendCapturePattern('[\-\+]', TimeZoneOffsetSign::NAME)
             ->appendCapturePattern(TimeZoneOffsetHour::PATTERN, TimeZoneOffsetHour::NAME)
+            ->startOptional()
             ->appendLiteral(':')
             ->appendCapturePattern(TimeZoneOffsetMinute::PATTERN, TimeZoneOffsetMinute::NAME)
+            ->endOptional()
             ->startOptional()
             ->appendLiteral(':')
             ->appendCapturePattern(TimeZoneOffsetSecond::PATTERN, TimeZoneOffsetSecond::NAME)
diff --git a/src/TimeZoneOffset.php b/src/TimeZoneOffset.php
index a9ac434..51933ec 100644
--- a/src/TimeZoneOffset.php
+++ b/src/TimeZoneOffset.php
@@ -106,7 +106,7 @@ public static function from(DateTimeParseResult $result): TimeZoneOffset
         }
 
         $hour = $result->getField(Field\TimeZoneOffsetHour::NAME);
-        $minute = $result->getField(Field\TimeZoneOffsetMinute::NAME);
+        $minute = $result->getOptionalField(Field\TimeZoneOffsetMinute::NAME);
         $second = $result->getOptionalField(Field\TimeZoneOffsetSecond::NAME);
 
         $hour = (int) $hour;
@@ -128,6 +128,7 @@ public static function from(DateTimeParseResult $result): TimeZoneOffset
      * The following ISO 8601 formats are accepted:
      *
      * * `Z` - for UTC
+     * * `±hh`
      * * `±hh:mm`
      * * `±hh:mm:ss`
      *
diff --git a/tests/TimeZoneOffsetTest.php b/tests/TimeZoneOffsetTest.php
index ad8fb38..b484dfc 100644
--- a/tests/TimeZoneOffsetTest.php
+++ b/tests/TimeZoneOffsetTest.php
@@ -152,6 +152,13 @@ public function testParse(string $text, int $totalSeconds): void
     public static function providerParse(): iterable
     {
         yield from [
+            ['+00', 0],
+            ['-00', 0],
+            ['+01', 3600],
+            ['-01', -3600],
+            ['+18', 64800],
+            ['-18', -64800],
+
             ['+00:00', 0],
             ['-00:00', 0],
             ['+01:00', 3600],
@@ -182,7 +189,6 @@ public static function providerParseInvalidStringThrowsException(): array
         return [
             [''],
             ['00:00'],
-            ['+00'],
             ['+00:'],
             ['+00:00:'],
             ['+1:00'],