If you live in the GMT or AEST timezones, this translates to 12:30am GMT/10:30am AEST on December 8 for the pre-show and 1am GMT/11am AEST on December 8 as well. The main show will begin at 5pm PT/8pm ET and is expected to run for roughly three hours according to The Game Awards website.
The Game Awards 2023 will kick off on December 7 with The Game Awards Opening Act at 4:30pm PT/7:30pm ET. How to Watch The Game Awards 2023 Livestream