CODEWITHSUNDEEP
wcfdatetimeiistimezone
mike waldron
mike waldron

Reputation: 11

IIS Reporting wrong Time and TimeZone

Everything i am reading says that IIS uses the local machine time and timezone, and as such to change the effective time zone and/or time, all i need do is change the time and timezone for the server, and it will change the effective time and timezone that the IIS server sees, and i have a server running a simple WCF service that this just does not seem to be working for me.

This server is is located on Pacific turf in a leased farm, but has had an Eastern timezone configured on it since we first set it up. I have tried resetting everything and even tried bouncing the box, so i am sure it is not cached Time values or something so simple. However upon break-pointing my WCF code to try and understand why it is passing out dates that are off by three hours to all consuming services, i found that IIS is convinced it is in Pacific Timezone, despite everything being configured otherwise.

System.TimeZoneInfo.Local reports that it is in Pacific Time, and DateTime.Now give me a timestamp that is off by three hours, and i can not seem to figure out how to convince IIS that it needs to use Eastern Time as the effective time zone for the records it is creating and handing out.

Upvotes: 1

Views: 5965

Answers (1)

Matt Johnson-Pint
Matt Johnson-Pint

Reputation: 241475

In general, server-side code should not depend on the local time zone. Calling either TimeZoneInfo.Local or DateTime.Now from a server application is usually a mistake. See The Case Against DateTime.Now.

The best practice would be to leave your server set to Coordinated Universal Time (UTC), and write your application to manage time zones internally. If you are dependent on Eastern time, then your code should do something like:

TimeZoneInfo tz = TimeZoneInfo.FindSystemTimeZoneById("Eastern Standard Time");
DateTime now = TimeZoneInfo.ConvertTimeFromUtc(DateTime.UtcNow, tz);

That said, if TimeZoneInfo.Local.Id is returning Pacific Standard Time, then there are only two possible explanations:

  • Your system is indeed set for the Pacific time zone.

  • Your system was set for the Pacific time zone, but you changed it without restarting or calling TimeZoneInfo.ClearCachedData.

Since you've eliminated both of these explanations in how you described the problem, I can only say that there must be something wrong with how you are setting the time zone.

Try using tzutil.exe on an Administrator elevated command prompt. tzutil /g will give you the current time zone setting. tzutil /s "Eastern Standard Time" will set your time zone for US Eastern Time. Be sure to restart your application after changing the time zone, either by recycling the application pool in the management console, using iisreset, restarting IIS, or (if you must) rebooting the server.

You can also just make the change through the time zone control panel.

If you are saying you've done all of that, and you're getting "Eastern Standard Time" back from tzutil /g, but TimeZoneInfo.Local.Id is returning "Pacific Standard Time" even though you've rebooted, then I call BS. That's just not possible. Perhaps there's a simpler explanation, such as maybe you're deploying to multiple servers and you're setting the time zone on a different server than you're getting the results from.

Upvotes: 3

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