Pi4 without rtc & updates

Is it possible having update problems without rtc?
Updated my pi4 and got trouble with the restart. Unfortunately I’ve no monitor in the room beside my wlanrouter, so I’ve not seen the 1st and 2nd boot sequence. The 3rd shows something like “the update could not be verifed” and “too old log dates”, but the 4th boot was fine and the pi with the installed update back on stage.