Do I need a shock-proof watch for cycling? I've just started cycling longer distances as a hobby (I cycle for my commute daily).

My watch isn't waterproof at all so I don't take it with me but on my last ride I found myself getting annoyed at regularly having to rummage in my bag for my phone to check what time it was.

I don't want a fancy GPS or sports watch that measures anything except time.

Obviously it would need to be waterproof enough for heavy rain (100m+? 30m?).

Would a simple digital (no moving parts to dislodge on a rough road) waterproof watch do the job or does it need to be shock proof (ie. G-Shock or similar) as well?
There are no special requirements for a watch for cycling. A cheap watch from the supermarkt will do as well as a decent quality watch or a sports watch (besides sport-specific functions).

Rain or road buzz might damage rather sensitive watches. Fixing a defect, loading the bike, or a crash also gives opportunities to damage a watch. Common sense will suffice to know when to take your horological masterpiece or leave it at home. In other words, there's a difference between riding to an opera and doing sports.

Most mechanical watches, for example a Seiko or something with an ETA movement, shouldn't be troubled by road buzz or the occasional cobble stretch. Please check reasonable voices in a watch forum.

Much sports riding is on a different level of impact, vibration, and risk of damage. In other words, mechanical watches are perhaps not the best choice for downhill MTB. A decent quartz watch or a G-Shock (analogue or digital doesn't matter) are preferable. Still, a dollar store digital will perform as well as the G.