Sleep timing guides
Plain-language guides with the math shown and the sources linked.
- Shift work sleep schedule: the basics from CDC/NIOSHHow to plan sleep around night shifts using CDC/NIOSH guidance: sleep right after the shift, a dark room, pre-shift naps and a day-off compromise.
- Caffeine and sleep: when to have your last cupWhat the FDA, a sleep-lab study and the Sleep Foundation say about caffeine timing, turned into clock times for a 10:30 PM bedtime.
- How long should a nap be? Power nap vs. full cycleWhy 20 minutes and 90 minutes are the two nap lengths sleep experts point to, why about 45 minutes can backfire, and how to time the alarm.
- Best time to go to bed if you wake up at 6, 6:30 or 7 AMBedtimes for 6:00, 6:30 and 7:00 AM alarms in 4, 5 and 6 sleep cycles, with a cycle-by-cycle timeline for each and the hours behind every option.
- The 90-minute sleep cycle, explained (and where it falls short)What a sleep cycle is, why 90 minutes is only an average, and how much a 10-minute difference in cycle length moves your ideal bedtime.
- How many hours of sleep do you need by age? The official tableThe CDC table of recommended sleep by age, from newborns to adults 65+, with the source behind each row and the bedtime each range implies.