Jewish_calendar no Internet

[MaxK (Mark)]

The short answer is no, it’s not easy.

Raspberry Pi 4 RTC

The cheap RTC boards don’t just work. Many are a DS3231 and need to be setup both on the kernel boot config.txt, and read / written with a privileged command. This might work if you run custom Debian with containers, but not with the deliberately locked-down HAOS. As MaxK just posted - wait 10 seconds after boot and the clock will be set from a remote Internet time server via NTP, so there’s no point (unless you’ve got no access…). Unlike the RPi4, the RPi5 has a hardware RTC and support…