Guide · BurnClock UV Timer
Why a UV timer beats guessing when to reapply sunscreen
Most people who care about anti-aging already own SPF 50. What they skip is the reapply. A weather app shows “UV 8.” A UV timer answers the only useful question: how many minutes until your skin actually burns today — and when to put another layer on.
Published 2026-09-22 · 8 min read
The two-hour rule is a floor, not a personal clock
Public guidance often says reapply about every two hours, and sooner after swimming or sweating. That is a useful default — and still a guess for fair skin at noon versus deeper skin in late afternoon. Live UV and phototype change the minutes. A generic timer that ignores both is marketing, not protection.
What “time to burn” actually means
- Fitzpatrick skin type is a rough map of how quickly unprotected skin reddens under UV.
- The UV index scales intensity for your location and hour — not a vanity weather badge.
- Together they produce an estimate of unprotected burn minutes. SPF and shade extend the window; sweating and swimming shorten protection.
Estimates are not a diagnosis. Seek shade and reapply before any countdown hits zero, and follow a clinician for medical skin concerns.
Why BurnClock is built around one moment
BurnClock is a UV reapply timer: personal time-to-burn from skin type + live UV, a full-screen burn countdown, an SPF reapply timer after you tap that you applied, a lock-screen nudge at zero, sky camera for filming, and a short sun-exposure log. It is not a 12-step skincare encyclopedia. Pro unlocks the full outdoor timers. Educational tracking only — not medical advice.
Frequently asked questions
Is a UV index enough to know when to reapply?
The index is intensity, not your clock. Pair it with skin type, SPF, and activity. BurnClock turns UV + phototype into a burn countdown and a reapply nudge.
Does BurnClock diagnose sun damage?
No. Times are estimates from UV and phototype. Seek shade, reapply early, and see a dermatologist for medical concerns.
BurnClock times are estimates from UV index and skin phototype, not a medical diagnosis. Seek shade and reapply before the clock hits zero.
BurnClock UV Timer
How many minutes until your skin actually burns today?
BurnClock is the UV reapply timer for people who already buy the serums — and still skip the two-hour sunscreen rule. Pick your skin type once. Live UV becomes a personal time-to-burn, then a full-screen countdown to your next reapply.