datetime to string with time zone
Solution 1:
Use the "zzz" format specifier to get the UTC offset. For example:
var dt = new DateTime(2010, 1, 1, 1, 1, 1, DateTimeKind.Utc);
string s = dt.ToLocalTime().ToString("yyyy-MM-dd HH:mm:ss \"GMT\"zzz");
Console.WriteLine(s);
Output: 2009-12-31 19:01:01 GMT-06:00
I'm in the CDT timezone. Make sure the DateTime is unambiguously DateTimeKind.Utc.
Solution 2:
If like myself you happen to need a format like 2018-03-31T01:23:45.678-0300
(no colon in the timezone part), you can use this:
datetime.ToString("yyyy-MM-ddTHH:mm:ss.fffzzz").Remove(26,1)
Solution 3:
This method will return the specified time in Eastern Standard Time (as the question requested), even if EST is not the local time zone:
public string GetTimeInEasternStandardTime(DateTime time)
{
TimeZoneInfo easternStandardTime = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
DateTimeOffset timeInEST = TimeZoneInfo.ConvertTime(time, easternStandardTime);
return timeInEST.ToString("yyyy-MM-dd hh:mm:ss tt\" GMT\"zzz");
}
Note: I haven't tested this in a non-English OS. See the MSDN documentation on TimeZoneInfo.FindSystemTimeZoneById.