EST US time zone.

Trailer must include footage rendered in game or a cinematic. A teaser with just a logo and/or title will not count. Just still images or concept art will also not count. A short trailer that still includes scenes from in-game will count even if people generally label it a “teaser trailer.”

A sequel to Half-Life: Alyx or something else positioned as a spin-off and not labeled Half-Life 3 still counts, I place no restrictions on the naming except that it must include “Half-Life” isn the title.