Convert Weeks to Days
Convert Weeks (wk) to Days (d) instantly and accurately.
Conversion Formula
d = wk × 7
About Weeks
A week (wk) = exactly 7 days = 604,800 s. The 7-day week derives from Babylonian astronomy assigning one of the seven classical celestial bodies to each day - preserved in English (Sun-day, Mon-day, Satur-day) and Romance language day names. It spread globally via Jewish, Christian, and Islamic calendars. ISO 8601 numbers weeks 1-52(53) with Monday as day 1. 365-day years contain 52 weeks + 1 day. 1 wk = 7 d = 604,800 s.
About Days
A day (d) = exactly 86,400 s. Earth's actual solar day varies ±16 s due to orbital eccentricity and axial tilt (equation of time). Leap seconds (abandoned in UTC after 2035) corrected the TAI-UT1 divergence. Mars's sol = 24 h 39 min 35 s ≈ 88,775 s; a Martian year = 668.6 sols. The day structures circadian biology, tides, and planetary science. 1 day = 86,400 s = 24 h.
Quick Reference Table
| Weeks (wk) | Days (d) |
|---|---|
| 1 wk | 7 d |
| 2 wk | 14 d |
| 5 wk | 35 d |
| 10 wk | 70 d |
| 25 wk | 175 d |
| 50 wk | 350 d |
| 100 wk | 700 d |