A healthy quartz watch typically keeps time within about 15 to 20 seconds per month, and many run tighter than that. If your quartz watch drifts noticeably within a week, something is off.
Why quartz is so accurate
A quartz movement times itself off a crystal vibrating 32,768 times per second, far steadier than any mechanical balance wheel. That's why a $30 quartz watch routinely out-times a mechanical watch costing a hundred times more, which might gain or lose that many seconds in a single day.
What makes a quartz watch drift more
- Temperature: quartz crystals are cut to be most accurate near room and wrist temperature. A watch left in a hot car or cold garage drifts more.
- Battery: a dying battery can cause erratic behavior before the watch stops. A seconds hand jumping in multi-second steps is often a low-battery warning, not a defect.
- Age and damage: impacts and worn components can degrade accuracy over years.
When to worry
Losing a few seconds a month: normal. Losing minutes a week: replace the battery first, and if that doesn't fix it, have the movement inspected. Quartz movements are often cheaper to replace than repair.
Related: Why Is My Quartz Watch Ticking Every Two Seconds? and Do Quartz Watches Ever Need Servicing?