C# - Convert DateTime or DateTimeOffset to and from unix timestamp

on C#

In C# you can easily convert a DateTimeOffset to Unix time in seconds or miliseconds using the built-in methods ToUnixTimeSeconds or ToUnixTimeMilliseconds:

var dateTimeOffset = DateTimeOffset.Now;
var unixTimeInSeconds = dateTimeOffset.ToUnixTimeSeconds();
var unixTimeMiliseconds = dateTimeOffset.ToUnixTimeMilliseconds();

The DateTime struct does not have this built-in method, so in order to use this you can convert your DateTime into a DateTimeOffset first:

var dateTimeOffset = new DateTimeOffset(DateTime.Now);
var unixTimeInSeconds = dateTimeOffset.ToUnixTimeSeconds();
var unixTimeMiliseconds = dateTimeOffset.ToUnixTimeMilliseconds();

You can create a DateTimeOffset from a unix time stamp in seconds or miliseconds using the built in FromUnixTimeSeconds

DateTimeOffset dateTimeOffset = DateTimeOffset.FromUnixTimeMilliseconds(1669321628392);
DateTimeOffset dateTimeOffset2 = DateTimeOffset.FromUnixTimeSeconds(1669321628);

In order to get a DateTime form a unix timestamp you can use the above and then convert the DateTimeOffset to a DateTime:

DateTimeOffset dateTimeOffset = DateTimeOffset.FromUnixTimeMilliseconds(1669321628392);
var dateTime = dateTimeOffset.DateTime;

That is all!

I hope you found the above helpful, please a leave a comment down below if you did!