Where is this setting? I only have a setting for changing the date/time
From the home screen, swipe left or right so you can see the " Settings" button, tap that. On one of the tabs (can't remember which one, might be "system", you may need to try several before you find the right one.) Scroll down the list you get after selecting the tab, you'll find something called Daylight Saving (or DST). It's then a simple toggle on/off. If the time's wrong after selecting "On", you'll need to adjust the time (again), but when the clocks change in future you'll only have to use the DST setting.