With Localisation Options open you'll be able to choose Change Timezone and select your local timezone.
From the command line, you can simply type
date and confirm the date is displayed in your desired timezone.
pi@raspberrypi:~ $ date Wed 28 Nov 11:10:33 PST 2018
The Raspberry Pi is a wonderfully flexible SBC and easily one of our favorite open-source boards on the market today.