Chosen Solution
My iMac always starts at the wrong time, I have reinstalled MacOS several times, but it did not solve the problem, can it be hardware?
Yes! You have a hardware issue the PRAM battery needs replacing! Sadly Apple placed it on the back side of the logic board so its a pain to get to! HEre’s the IFIXIT guide: iMac Intel 21.5" EMC 2308 PRAM Battery Replacement
