Worldwide Pokémon Direct to held at midnight on 20th anniversary
Feb. 26 in North America and Europe, Feb. 27 in Japan
A Pokémon Direct presentation will be streamed worldwide later this week. It will be held at midnight at the start of the Pokémon 20th Anniversary (according to the time in Japan). This corresponds to 3 pm on Feb. 26 in UTC.
For the time your time zone, see this link.
The Japanese Pokémon Direct will run for 5 minutes. It is unclear if the North American and European Pokémon Directs will also be the same length, but it is likely that they will be.
A Pokémon Direct is a special Pokémon-focused version of a Nintendo Direct, which is a type of livestreamed video presentation Nintendo uses to announce new products and content. The only other time a Pokémon Direct has been held was in January 2013, which announced Pokémon X and Y.