Having problems with converting my DateTime to UTC

Question

I am storing all my dates in UTC format in my database. I ask the user for their timezone and I want to use their time zone plus what I am guessing is the server time to fig

Answer 1

Everyone else's answer seems overly complex. I had a specific requirement and this worked fine for me:

void Main()
{
    var startDate = DateTime.Today;
    var StartDateUtc = TimeZoneInfo.ConvertTimeBySystemTimeZoneId(DateTime.SpecifyKind(startDate.Date, DateTimeKind.Unspecified), "Eastern Standard Time", "UTC");
    startDate.Dump();
    StartDateUtc.Dump();
}

Which outputs (from linqpad) what I expected:

12/20/2013 12:00:00 AM

12/20/2013 5:00:00 AM

Props to Slaks for the Unspecified kind tip. That's what I was missing. But all the talk about there being only two kinds of dates (local and UTC) just muddled the issue for me.

FYI -- the machine I ran this on was in Central Time Zone and DST was not in effect.