I tried everything to set a default timezone in browsers for timpicker js but it's not working.
Here is the js i am using : http://trentrichardson.com/examples/timepicker/jquery-ui-timepicker-addon.js
And its customization options are : http://trentrichardson.com/examples/timepicker/
You can add
where +0400 is your preferred default time zone and you'll be on your merry way.