Setting a watch is a pretty straightforward process, but it does have some dos and don’ts. The most important rule is not to set the date if the watch’s time is between 9 p.m. and 2 a.m. Note that we said “the watch’s time”, not the actual time of day. If you pick up a watch that isn’t running and you aren’t sure when it stopped, pull the crown all the way out and spin the hands until the date changes. Then you’ve found midnight; next, advance the time past 2 a.m. before pushing the crown in to set the date. Why, you ask? The date-changing mechanism starts to engage the gear train after 9 p.m. and only disengages after 2 a.m. Setting the date during this period can break off the delicate teeth of the mechanism, resulting in a costly repair. It’s also a good idea to set a watch forward rather than running it backwards. This is, again, to prevent damage to the date mechanism. Of course, if your watch doesn’t display the date, none of this matters.

Archenemies
As we mentioned above, the mortal enemies of a mechanical watch are moisture, shock and magnets. Fortunately, modern timepieces are pretty good at resisting all three. Synthetic gaskets, screw-down crowns and tight tolerances keep water out of a watch — assuming they’re all in good shape. Most watches, even dress watches, are rated for water resistance to at least 3 atmospheres, which is equivalent to roughly 30 meters. That may sound deep, but it’s nearly the minimum rating for a watch, so though your Patek Calatrava will probably survive a dunk in the pool at a bachelor party, we don’t advise taking it for your daily morning swim. (For that, stick with a timepiece rated to at least 50 meters.) While screw-down crowns are the best insurance against moisture, even some 200-meter rated dive watches use robust double-sealed free-spinning crowns. Regardless, if you spend a lot of time in the water (by choice or by accident), it’s a good idea to have your watch’s water resistance tested annually, and to have gaskets replaced.