For a while I had a low-power server for my personal things that stayed on all the time, and a more powerful computer that hosted a minecraft server. As the player count dwindled, I decided to make the minecraft server automatically shut down at midnight, and wake up at 8 in the morning using rtcwake. And eventually I disabled the rtcwake thing entirely, and made the smaller server run a webui that could wake up the minecraft server using wake-on-lan. So if anyone wanted to play, they would first have to remotely turn on the server through a web page. This was all password-protected ofcourse.
Also, no, I don’t use a UPS. I’ve never seen anyone use a UPS in the country where I live, and I don’t think I’ve experienced a power outtage in like 4 years. Whether or not you need a UPS seems to be largely dependent on where you live.