Complicated Watches Explained — How They Work and What to Look For

A complication is any function beyond hours, minutes and seconds.

Annual versus perpetual calendar

An annual calendar needs one correction a year at the end of February. A perpetual also knows the leap cycle and, kept running, needs none until 2100. The mechanical gap between them is large.

Moonphase accuracy

A standard moonphase drifts a day every two and a half years; a high-precision version drifts a day in about 122 years. Both are decorative, which is the charm.

Setting rules that protect the movement

Never change the date between roughly 9 pm and 3 am while the change-over gearing is engaged. On a stopped perpetual, wind fully and advance through the missing days rather than jumping the date.

Servicing

Parts are rarely generic. Confirm the manufacture or a competent independent still supports the calibre before buying.

How Chrono24 Watches applies this

Every watch we list is opened and inspected before it appears on the site. We verify the calibre against the reference, examine dial printing and lume ageing under magnification, record timing across multiple positions on a calibrated timegrapher, measure bracelet stretch, and pressure-test sports references with intact cases. What we find is published on the listing, including the flaws, and photographed. You can read the full process on our authentication page.

Buying with confidence

Shipping is free, fully insured and requires a signature on delivery. You have fourteen days from delivery to return any watch for a full refund, for any reason, using a prepaid insured label, and every mechanical watch carries a twelve-month warranty on the movement. Our authenticity guarantee has no expiry date. If this is your first purchase from us, start with how to buy.

Next steps

Browse the current complicated collection, or move across to chronographs, dive watches and dress watches to compare.