Determine a user's timezone

html browser timezone user-agent timezone-offset
Kevin Dente picture Kevin Dente · Aug 1, 2008 · Viewed 211.7k times · Source

Is there a standard way for a web server to be able to determine a user's timezone within a web page?

Perhaps from an HTTP header or part of the user-agent string?

Answer

JD Isaacks picture JD Isaacks · Nov 27, 2009 
-new Date().getTimezoneOffset()/60;

The method getTimezoneOffset() will subtract your time from GMT and return the number of minutes. So if you live in GMT-8, it will return 480.

To put this into hours, divide by 60. Also, notice that the sign is the opposite of what you need - it's calculating GMT's offset from your time zone, not your time zone's offset from GMT. To fix this, simply multiply by -1.

Also note that w3school says:

The returned value is not a constant, because of the practice of using Daylight Saving Time.

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