Why does the timer restart or show the wrong time?

How the timer counts depends on Timer type in Timer Setting.

It starts again on every page. Fixed minutes after page load starts from the same number of minutes each time a shopper opens a page. To count to a fixed end, use Count to date. With Loop countdown, the timer also starts again when it reaches zero.
It ends at a different hour for some shoppers. Count to date ends at one moment for everyone, so the clock time differs by time zone. Select Ignore customer timezone to end at the same clock time in every time zone.
It does not show in the morning. Daily recurring is hidden before its Start time each day and counts down to its End time, using the shopper's device clock.
It shows 00:00:00. The timer ended and Endtime Behavior is Stop at zero. Choose Disappear to hide it or Show custom title to change the text.