Convert time units — seconds, minutes, hours, days, weeks, months, years.
| Unit | Name | Value |
|---|---|---|
| ms | Millisecond | 86400000 |
| s | Second | 86400 |
| min | Minute | 1440 |
| hr | Hour | 24 |
| wk | Week | 0.14285714 |
| mo | Month (30d) | 0.033333333 |
| yr | Year | 0.002739726 |
Formula: Week = Day × 0.1429
Multiply any day value by 0.1429 to get week.
Reverse: Day = Week × 7
Common day values — factor: 1 d = 0.1429 wk
| Day (d) | Week (wk) | Context |
|---|---|---|
| 1 d | 0.1429 wk | One day |
| 7 d | 1 wk | One week |
| 14 d | 2 wk | Two weeks |
| 30 d | 4.286 wk | One month |
| 90 d | 12.86 wk | One quarter |
| 180 d | 25.71 wk | Half year |
| 365 d | 52.14 wk | One year |
| 730 d | 104.3 wk | Two years |
| 1,825 d | 260.7 wk | 5 years |
| 3,652 d | 521.8 wk | One decade |
| 7,305 d | 1,044 wk | 20 years |
| 3.652e+04 d | 5,218 wk | One century |
| 3.652e+05 d | 5.218e+04 wk | One millennium |
| 3,652,000 d | 5.218e+05 wk | 10,000 years |
| 36,520,000 d | 5,218,000 wk | 100,000 years |
Days ÷ 7 = weeks. Exact.
7 d = 1 wk, 28 d = 4 wk, 365 d = 52.14 wk.
Weeks × 7 = days.
Plans project timelines and milestone durations in days using Gantt charts.
Calculates lead times, delivery windows, and inventory turnover in days.
Prescribes medication courses in days and tracks patient recovery timelines.
Plans crop cycles, irrigation schedules, and harvest windows in days.
Manages leave balances, probation periods, and notice periods in working days.
Calculates statutory deadlines, appeal windows, and contract terms in days.
The day (86,400 seconds) is defined by Earth's rotation period relative to the Sun. Ancient civilizations independently divided the day into 24 hours — Egyptians used sundials and water clocks as early as 1500 BCE.
Days are the fundamental unit of the Gregorian calendar and human biological rhythm (circadian cycle). Stock markets, shipping logistics, medication dosing, and agricultural planning all operate on daily cycles.
Interesting fact: A 'sidereal day' (Earth's rotation relative to stars) is 23 hours 56 minutes 4 seconds — about 4 minutes shorter than the 24-hour solar day we use.
The 7-day week has no astronomical basis — unlike the day, month, or year. Its origin is traced to Babylonian astronomy (assigning planets to days) and Jewish tradition (the biblical 7-day creation), later adopted by Rome and spread globally.
The week is the standard unit for work schedules, academic timetables, and business cycles across virtually every culture. The ISO 8601 standard defines Monday as the first day of the week.
Interesting fact: The French Revolutionary Calendar (1793–1805) attempted a 10-day week (décade). It was deeply unpopular and abandoned within 12 years.
Converting day to week is a common task across science, engineering, and everyday planning. The time scale spans from nanoseconds in computing to centuries in history, and having accurate conversions helps when comparing measurements across different systems or disciplines.
As a quick reference: 5 d = 0.7143 wk and 10 d = 1.429 wk. For the reverse: 1 wk = 7 d. The exact conversion factor is 1 d = 0.1429 wk.
All conversions are performed in IEEE 754 double-precision arithmetic, accurate to at least 8 significant figures.