DateTime in REST Api

Hello,

excuse the stupid question, but how does the conversion of dates in the REST API?

The date is in Unix format time but I can not write write it correctly.

If something is not wrong

var instanceTime = (DateTime.Now - (new DateTime(1970,1,1)).TotalSecond;

(DateTime.Now - (01/01/1970)) take the number of seconds

is that correct? works with the date format UTC

Thank you