Tried rebooting.
Mine is OK with an aerial feed. Are you on aerial or IP & which region?
Oddly we had an issue on 1st March last year. Maybe BT/YouView software can't cope with a short February?
Mine is on Wednesday 1st in IP mode.
There was this advice on something similar last year
https://community.bt.com/t5/YouView-from-BT/Incorrect-today-s-date-on-tv-guide/td-p/2218348
https://community.bt.com/t5/YouView-from-BT/BT-TV-Box-Pro-issue-Update-02-03-2022/m-p/2218158