Get timezone from DateTime

c# .net datetime timezone
dbkk picture dbkk · Feb 23, 2009 · Viewed 99.4k times · Source

Does the .Net DateTime contain information about time zone where it was created?

I have a library parsing DateTime from a format that has "+zz" at the end, and while it parses correctly and adjusts a local time, I need to get what the specific time zone was from the DateTime object.

Is this possible at all? All I can see is DateTime.Kind, which specifies if time is local or UTC.

Answer

Jon Skeet picture Jon Skeet · Feb 23, 2009

DateTime itself contains no real timezone information. It may know if it's UTC or local, but not what local really means.

DateTimeOffset is somewhat better - that's basically a UTC time and an offset. However, that's still not really enough to determine the timezone, as many different timezones can have the same offset at any one point in time. This sounds like it may be good enough for you though, as all you've got to work with when parsing the date/time is the offset.

The support for time zones as of .NET 3.5 is a lot better than it was, but I'd really like to see a standard "ZonedDateTime" or something like that - a UTC time and an actual time zone. It's easy to build your own, but it would be nice to see it in the standard libraries.

EDIT: Nearly four years later, I'd now suggest using Noda Time which has a rather richer set of date/time types. I'm biased though, as the main author of Noda Time :)

Related questions

DateTime vs DateTimeOffset

Currently, we have a standard way of dealing with .NET DateTime's in a TimeZone aware way: Whenever we produce a DateTime we do it in UTC (e.g. using DateTime.UtcNow), and whenever we display one, we convert back from …

Read More
Creating a DateTime in a specific Time Zone in c#

I'm trying to create a unit test to test the case for when the timezone changes on a machine because it has been incorrectly set and then corrected. In the test I need to be able to create DateTime objects …

Read More
Create DateTime from string without applying timezone or daylight savings

How do I create a DateTime var from a string which is already adjusted for UTC? I am running this on a machine set to BST (GMT+1). If I run the following line of code: DateTime clientsideProfileSyncStamp = Convert.ToDateTime("20-May-2011 15:20:00"); …

Read More