Problem Description
I experienced an extended power outage; after the power was restored and the freedombox powered on, I ran the diagnostics app and found the time is now out of sync. After running the timedatectl command several times, I found the local/universal time and the rtc time are drifting apart. Note the difference in time goes from 8 min 10 sec to 8 min 36 sec.
RTC will frequently keep poor time and drift. If this is a concern use NTP. I believe FB is using SNTP (not NTP) which is usually good enough. NTP has a clock discipline feature to fix RTC drift and allow the computer to keep (more) accurate time when disconnected from network time sources.
SNTP protocol is compatible with NTP and you may see SNTP referred to as NTP, but they are not functionally interchangeable. NTP is the industrial strength server solution and SNTP is for clients. SNTP will not fix the system clock drift but NTP will.
