Как создать временную метку UTC Unix в С#

Ответ 1

private double ConvertToTimestamp(DateTime value)
{
    //create Timespan by subtracting the value provided from
    //the Unix Epoch
    TimeSpan span = (value - new DateTime(1970, 1, 1, 0, 0, 0, 0).ToLocalTime());

    //return the total seconds (which is a UNIX timestamp)
    return (double)span.TotalSeconds;
}

Ответ 2

DateTime.UtcNow - new DateTime(2012,10,10,14,0,0)).TotalSeconds