Common DatetimeOffset usage with C#

The DateTimeOffset structure includes a DateTime value, together with an Offset property that defines the difference between the current DateTimeOffset instance's date and time and Coordinated Universal Time (UTC)

It represents dates and times with values whose UTC ranges from 12:00:00 midnight, January 1, 0001 Anno Domini (Common Era), to 11:59:59 P.M., December 31, 9999 A.D. (C.E.).

How to use DateTimeOffset

Create DateTimeOffset object

DateTimeOffset = DateTime + Offset path, so usage is similar to DateTime

DateTimeOffset today = new DateTimeOffset();
Console.WriteLine(today); // 01/01/0001 00:00:00 +00:00

today.Should().Be(DateTimeOffset.MinValue); // True

// Local time of machine 8 Jan 2024 10:08
today = DateTimeOffset.Now;
Console.WriteLine(today); 08/01/2024 10:07:16 +07:00

+00:00 and + 07:00 is offset specific part

Create DateTimeOffset object

var today = new DateTimeOffset(2024, 1, 1, 11, 30, 00, new TimeSpan(7, 0, 0));
Console.WriteLine(today); // 01/01/2024 11:30:00 +07:00

Console.WriteLine(DateTimeOffset.Now);     // Local machine Vietnam UTC+7 time  08/01/2024 11:40:38 +07:00
Console.WriteLine(DateTimeOffset.UtcNow); // Basis of utc time (UTC or UTC+0)   08/01/2024 04:40:38 +00:00

Format DateTimeOffset object

Sample UTC time in ISO-8601 format: 2024-01-01T12:12:34+00:00 Format pattern: "dd-MM-yyyy HH:ss:mmzzz"

Console.WriteLine(DateTimeOffset.UtcNow.ToString("dd-MM-yyyy HH:ss:mmzzz")); // 08-01-2024 04:43:48 +00:00

More format patterns sample at https://learn.microsoft.com/en-us/dotnet/standard/base-types/custom-date-and-time-format-strings

Parse UTC time from ISO-8601 string

var utcTimeString = "2024-01-01T11:30:00+07:00";
var utcTime = DateTimeOffset.ParseExact(utcTimeString, "yyyy-MM-ddTHH:ss:mmzzz", CultureInfo.InvariantCulture);
// Format ISO-8061 to better readable pattern
Console.WriteLine(utcTime.ToString("dd-MM-yyyy HH:ss:mm zzz")); // 01-01-2024 11:30:00 +07:00

Code example at: Github