According to the wiki (middle of the first paragraph), they update it once per year in January. The war began in February.
The Bulletin addresses the Russian invasion of Ukraine on March 7, 2022 and explicitly left the clock at 100 seconds to midnight. The Bulletin's website says they meet at least twice a year to discuss the state of things. The last many (20) years have seen an announcement made each year near the end of January, but historical it looks like they've changed the clock in response to specific events throughout the year.
https://thebulletin.org/2022/03/bulletin-science-and-securit...
https://thebulletin.org/doomsday-clock/timeline/#footer_menu...