datetimeoffset

DateTimeOffset is a value type in the System namespace that represents a point in time along with an offset from Coordinated Universal Time (UTC). It combines a DateTime value with a TimeSpan offset, such that the offset indicates how far the time is from UTC. For example, 2023-07-06T12:34:56+02:00 represents the same instant as 2023-07-06T10:34:56Z.

DateTimeOffset is not a time zone; it does not contain time zone rules or daylight saving information. It simply records the offset; the actual time zone for display or calculations must be determined separately if needed.

A DateTimeOffset value can be converted to UTC via ToUniversalTime or to another offset via ToOffset. The UtcDateTime property returns the corresponding UTC DateTime. The DateTime property returns the local time component as a DateTime with the stored offset. It can be compared, added to, and subtracted from other DateTimeOffset values.

It supports parsing from strings and formatting to strings, typically using ISO 8601 with offset. It implements standard interfaces such as IComparable<DateTimeOffset> and IEquatable<DateTimeOffset>, and is widely supported by .NET JSON serializers.

Common use cases include representing a specific moment with its offset for logging, serialization, or inter-system communication where preserving the offset is important. While DateTimeOffset carries offset information, it does not encode time zone rules, so time zone conversions (e.g., DST transitions) should use a time zone-aware provider when necessary.