Here are the timers that i have on my system, frstrim was running yesterday but the on saturday i also had a freeze
Mon 2020-05-18 12:58:26 CEST 39min left Mon 2020-05-18 11:58:26 CEST 20min ago snapper-cleanup.timer snapper-cleanup.service
Mon 2020-05-18 13:00:00 CEST 40min left n/a n/a snapper-timeline.timer snapper-timeline.service
Tue 2020-05-19 00:00:00 CEST 11h left Mon 2020-05-18 00:00:01 CEST 12h ago logrotate.timer logrotate.service
Tue 2020-05-19 00:00:00 CEST 11h left Mon 2020-05-18 00:00:01 CEST 12h ago man-db.timer man-db.service
Tue 2020-05-19 00:00:00 CEST 11h left Mon 2020-05-18 00:00:01 CEST 12h ago shadow.timer shadow.service
Tue 2020-05-19 00:00:00 CEST 11h left Mon 2020-05-18 00:00:01 CEST 12h ago updatedb.timer updatedb.service
Tue 2020-05-19 06:03:54 CEST 17h left Mon 2020-05-18 06:03:54 CEST 6h ago etckeeper.timer etckeeper.service
Tue 2020-05-19 06:03:54 CEST 17h left Mon 2020-05-18 06:03:54 CEST 6h ago systemd-tmpfiles-clean.timer systemd-tmpfiles-clean.service
Mon 2020-05-25 00:00:00 CEST 6 days left Mon 2020-05-18 00:00:01 CEST 12h ago fstrim.timer fstrim.service