That was the day I started creating a written Timeline for all of my stories. A formal Timeline helps me:
- keep track of where characters are supposed to be
- helps me to make sure that when different characters converge, the knowledge they possess is consistent with what they're supposed to know where and when they are in the story
- make sure I'm not cramming too much into a given set of hours
My Timeline started as sketched notes on a piece of paper. I've since moved to a spreadsheet that keeps things much easier to read. My column headers are Day One, Day Two, Day Three, etc.; my row headers are the hours, 12am through 11pm.
With The Book, the two major characters are together much of the time so I don't have to keep track of them separately. If they weren't, I'd have separate columns for each character and would give each character's column a separate color to help me visually.
Making sure your characters don't work non-stop through days and days not only gives them a break, but gives your reader a break. Hopefully your readers will be so swept up in your characters and story that they'll be relating closely with what your characters are doing. Even if your fictional people don't need a sense of downtime, your readers do.
Of course, some fictional characters don't need a break in their 24 hour day. Although, if the writers made their characters more believable, they should.