I usually animate (basically drawing) for the entire day without breaks (not very good for your eyes imo lol) Unless you're talking about drawing on physical paper, then it takes about 20 hours for a full blown, wild drawing
Not a fan of digital I prefer to have something physical
When it's a school day I don't draw at all but I animate on my laptop during lunch breaks
When it's a weekend I... uh.. sleep.
Gotta catch all those zzz's.