Creating a world clock app that accounts for Daylight Savings Time RRS feed

  • Question

  • User-1380711633 posted

    I need to create an application that displays the local time for a user, plus a drop down that allows them to select one of dozens of locations around the world and display the local time in that location.  It has to be a real-time clock, that is, a clicking clock, not a static time displayed upon load. 

    I had something written in JavaScript that displayed a realtime clock and then handled normal GMT/UTC deviations for any selected location.  This wasn't too bad.  Then I realized that it didn't take into account that some of the locations use DST and at different times of the year and for certain durations.  I had thought about trying to use .NET to somehow tap into the user's local Date and Time settings which seem to have Time Zone data at the OS level, but I have no idea how to get to that data, and it seems like having the user's local time be the basepoint and them having the ability to check/uncheck to adjust for DST is going to be problematic.

    Basically, I need to be able to get a reliable current time for anywhere in the world, regardless if they are currently within DST or not.  And, I need to be able to plug the data into my current client script so the values can be real-time and not rely on post-backs (what a nightmare that would be!).

    Has anyone had any experience in doing this successfully in a production environment?  This is for internal use, not commercial use.  It will be used on our Intranet home page.

    Any advice is greatly appreciated.



    Monday, November 20, 2006 12:35 PM

All replies

  • User1416329745 posted

    I don't know how it is done because it is very complex but what you are looking for already exist.  Hope this helps.


    Monday, November 20, 2006 4:50 PM
  • User1347187933 posted


    Daylight saving is kept changing according to local law or policy though is not that frequent. In your scenario, I think you can just keep a list of locations if they have Daylight Saving.



    Wednesday, November 29, 2006 2:15 AM