Here was the timeline for 2021 admission decisions and each campus has a different timeline when they post their decisions. Some will notify applicants of a specific date and some will not.
2021 decisions;
UCB: Last year, Early admits were Feb 10, 2021 and Regular Decision was March 25.
UCLA: 3rd Friday of March. Last year it was March 19.
UCSD: Last year, March 19
UCSB: Last year, March 16
UCD: Last year, March 18
UCI: Early CHP/Regents last year was March 5. Regular decisions in waves March 12.
UCSC: Last year rolling waves Feb 22-March 20
UCR: Last year rolling decisions starting March 1
UCM: Last year rolling decisions starting March 2.
As the UC’s start posting decision dates, myself or @lkg4answers will update each specific UC forum with the information.