“systemctl list-timers” shows last executed dates that are far in the future

When I run systemctl list-timers, the last executed dates are far in the future. For example, this is part of the output:

$ systemctl list-timers
NEXT                          LEFT                    LAST                          PASSED                  UNIT                         ACTIVATES
Sat 2017-08-19 02:29:16 CEST  6h left                 Wed 2017-08-16 02:50:57 CEST  2 days ago              systemd-tmpfiles-clean.timer systemd-tmpfiles-clean.service
Sun 2092-06-29 22:30:00 CEST  74 years 10 months left Sun 2092-06-29 00:22:17 CEST  74 years 10 months left rsnapshot-daily.timer        rsnapshot@daily.service
Mon 2092-06-30 00:00:00 CEST  74 years 10 months left Sun 2092-06-29 00:22:17 CEST  74 years 10 months left fstrim.timer                 fstrim.service
Mon 2092-06-30 00:00:00 CEST  74 years 10 months left Sun 2092-06-29 00:22:17 CEST  74 years 10 months left logrotate.timer              logrotate.service
Mon 2092-06-30 00:00:00 CEST  74 years 10 months left Sun 2092-06-29 00:22:17 CEST  74 years 10 months left man-db.timer                 man-db.service

When I checked my backup, which should be triggered by the rsnapshot-daily.timer job, I noticed that it stopped working about one week ago. Thus, it looks like the systemd timers are partly broken on my system.

I assume the problem will go away if I reboot my machine. Still, I am curious if it is a known problem and whether there any workarounds?

Restarting the timers did not make a difference (e.g., systemctl restart rsnapshot-daily.timer). The last executed dates are still in 2092.

I'm using systemd version 234.11-8 on Arch Linux.