The timezone setting in Facebook comes from the timezone setting on your computer. If your Facebook posts seem to be traveling through time, there may be something wrong with your computer’s time settings.
How to Change Facebook Timezone Settings
Log out your Facebook account.
Close your Internet browser.
Click the digital clock in the lower right corner of your screen.
Click the blue Change Date and Time Settings in the bottom of the drop-down menu.
Click Change Time Zone.
This opens the Time Zone Settings window.
Select the correct time zone from the drop-down menu.