DateTimeField and timezone conversion problem

Question

It seems that the datetime value which is entered into a DateTimeField is always stored as UTC no matter what timezone is configured for the current user.

Only the output on the page is displayed in the correct timezone format. So for me (UTC+3) the time displayed on the page is always +3 hours form the time that I've entered into the field. How can I avoid that?

For example if I enter 2011/01/01 5PM into the DateTimeField and publish the page the displayed date is 2011/01/01 8PM.

Answer 1

Problem is in method "onBeforeRendering", right after changing timezone of date, there is an used object named MutableDateTime, which kills all timezone settings. So this object returns correct time, but displays incorrect one

Answer 2

For SharePoint with users from different timezones the only working solution is to store all DateTimes in UTC format. This is the only time (zone) that's not affected by Daylight saving changes and other stuff.

This behavior is by design and it cannot be changed, however there are methods that help you display correct time. Check article Converting Date and Time Values as your starting point.

Answer 3

As Toni says when setting a date/time programatically you should use UTC.

The time zone that will be used for the display is set at the Web's level (regional setttings).

To convert between the web sites time zone to UTC you should get the webs time zone from the regional settings property and use the LocalTimeToUTC method

So something like

SPTimeZone timeZone = SPContent.Current.Web.RegionalSettings.TimeZone;
listItem[fieldName] = timeZone.LocalTimeToUTC(localTime);

Answer 4

It seems to be a SharePoint Bug. Normally the User Controls convert the time to the current user's time zone in the rendering process. This does not work well in DateTimeFields. We have an open ticket with MS regarding this problem. I will post the results as soon as we have a reliable answer.