Wrong date and time display because CEST vs. CET timezone (where does gnome reads the timezone if not from the system setting?)
Gnome somehow disagrees with the system timezone, namely currently there is Central European Summer Time but Gnome thinks it's already non-summer time.
$ timedatectl
Local time: cs 2020-10-08 10:07:26 CEST
Universal time: cs 2020-10-08 08:07:26 UTC
RTC time: cs 2020-10-08 08:07:26
Time zone: Europe/Budapest (CEST, +0200)
System clock synchronized: yes
NTP service: active
RTC in local TZ: no
But gnome setting timezone says it's CET already. Result: time in gnome (only in gnome) is 1 hour late. Screenshot attached.