Basky’s glossary exists so nobody has to decode a sky number or a skin-type label alone. The product speaks warmly on purpose: short words, honest limits, zero shame if you miss a day. This page is the map. Each term below has a one-line meaning and a link to a fuller guide.

If you landed here from an answer engine, start with safe-sun window and Fitzpatrick type — those two ideas unlock almost everything else Basky shows on the Today screen.

How to use this hub

  1. Skim the table for the word you saw in the app.
  2. Open the linked guide when you want the “why,” not just the “what.”
  3. For product questions (free vs Forever, Circles, Health, shipping), jump to the FAQ.
  4. For the ritual in one breath, read how Basky works.

Nothing here is a clinical protocol. Basky offers general wellness guidance, not medical advice.

Terms at a glance

TermPlain meaningDeeper guide
Safe-sun windowYour personal minutes of gentle direct sun for today’s UV and skin typeMeaning · How long?
Minimal erythemal dose (MED)The UV dose that would just begin to redden skin; Basky targets ~60% of itMED explained
Erythemally weighted UVUltraviolet counted by how likely it is to redden skin — the basis of the UV indexWeighted UV · UV index
UV band labelsLow / Moderate / High / Very high / Extreme — plain labels for the indexBand labels
Fitzpatrick typeA six-type scale of how skin tends to burn or tan; Basky’s personalization inputType meaning · App landing
Vitamin D estimateA friendly on-screen figure, capped with the safe window — not a lab resultEstimate meaning · Product
Daylight streakConsecutive days you met a gentle outdoor goal; cloudy forgiveness built inStreak meaning · Streak
Sunshine CircleOptional private group that shares a first name and sun days — no leaderboardsCircle meaning · Circles
Open-Meteo UVThe weather source Basky uses for live UV when location is allowedSee FAQ · Privacy
Basky ForeverOne-time cosmetic unlock; the wellness core stays free foreverSee FAQ

The ideas that hold the product together

Personal, not universal. The same noon UV is a different story for type I skin than for type VI. Basky refuses a one-size timer. Your type is a soft self-description from onboarding — warm copy, not a ranking of “better” skin.

Conservative by design. The window aims near 60% of MED, then clamps. That is the anti-shame safety rail: enough daylight to feel the habit, never a reward for going past the line.

Estimate, not oracle. Vitamin D on screen is painted as an estimate so nobody confuses Basky with a clinic. Apple Health, if enabled, receives only write-only Time in Daylight — never the estimate, never a read of your Health library.

Social without surveillance. Circles celebrate “you caught the sun” with people you invite. They do not export location, streaks, or rankings. There is still no account.

Sky literacy without anxiety. UV band labels translate the index into human language. High UV shortens a window; it does not mean “you failed at outdoors.” Low UV still counts for a daylight check-in.

A short reading path

New to sun science? Try this order:

  1. What is the UV index?
  2. Erythemally weighted UV
  3. MED
  4. Safe-sun window meaning
  5. Fitzpatrick type meaning

Curious about the habit loop? Then daylight streak, vitamin D estimate, and Sunshine Circles.

Searching for a Fitzpatrick skin type app? The product-and-education landing is Fitzpatrick skin type.

What this glossary will never do

  • Shame pale skin, deep skin, or anyone who stayed inside.
  • Sell “tan goals,” burn challenges, framing.
  • Pretend a phone can replace sunscreen, clothing, shade, or a clinician.
  • Pretend Basky is a ranking, a lab, or a clinic. It is a live iPhone habit on the App Store — wellness, not medicine.

Browse the table, open a guide, or ask the FAQ. The words stay gentle on purpose — because a little sunshine should feel like an invitation, not a test.