Somnly: Shift Work Sleep Calculator

Somnly is a sleep planner built for one job: helping shift workers sleep. Enter a single shift or a full rotating roster, and it suggests when to sleep before and after each shift, when a nap will help on nights, and how much sleep debt is building across the rotation.

It is made for the people whose hours do not fit a normal sleep app: nurses and doctors, emergency services, pilots and cabin crew, and anyone working nights in factories, warehouses, mining or hospitality. The guidance follows your circadian rhythm whether you are on days, nights or a rotation that changes every week.

Somnly is free, with no ads and no account, and your sleep and shift data stays on your iPhone. It is a general wellness tool, not a medical device: if you have ongoing sleep problems, talk to a health professional, and never drive or operate machinery when you are drowsy.