systemd timer runs more than once per period even with persistent=false

I have a unit that normally I want running, but sometimes I want to manually shut it off for the day and restart it later automatically. So I have a timer to restart it OnCalendar=daily. This works, but sometimes I need to stop the unit twice because the timer immediately restarts the unit. Here's a simplified example with minutes instead of days: [Unit] Description=foo timer [Timer] Persistent=false OnCalendar=minutely AccuracySec=1 Unit=foo.service [Install] WantedBy=default.target --- [Unit] Description=foo service [Service] Type=simple ExecStart=/bin/sh -c 'while true; do sleep 1; done' [Install] WantedBy=default.target --- If I systemctl stop foo.service, and the timer had fired more than 1 minute ago (PASSED > 1m in systemdctl list-timers), it immediately refires and starts the unit. The unit always stays stopped until the next minute if I stop it twice. The docs make it sound like Persistent=false should not cause this, but clearly I'm misunderstanding. If it matters, the daily unit I'm actually interested in is a system unit, but the test unit is a user unit; the behavior is the same.