1 Week equals 7 Days.
| Week (wk) | Day (d) |
|---|---|
| 0.001 wk | 0.007 d |
| 0.01 wk | 0.07 d |
| 0.1 wk | 0.7 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 |
| 500 wk | 3,500 d |
| 1,000 wk | 7,000 d |
To convert Weeks to Days, multiply the value by 7. This factor comes from the ratio of the two units' definitions: one Week equals 7 Days.
For example: 1 Week = 7 Days, and 10 Weeks = 70 Days.
To convert in the reverse direction — from Days to Weeks — multiply by 0.142857.
The week is a period of 7 days, an interval with ancient origins that is not directly tied to any astronomical cycle. The 7-day week is believed to have originated in ancient Mesopotamia, influenced by the number of celestial bodies visible to the naked eye (the Sun, Moon, Mercury, Venus, Mars, Jupiter, and Saturn) and the approximately 28-day lunar cycle divided into four quarters. The week spread through Jewish, Greek, Roman, and eventually Christian and Islamic traditions until it became universal.
Today the 7-day week is used by virtually every culture on Earth and is the basis for social, legal, and religious scheduling worldwide. The concept of the weekend — days set aside from work — varies by culture (Friday-Saturday in some Muslim-majority countries, Saturday-Sunday in most others), but the 7-day structure itself is consistent. The week underlies employment law (40-hour workweeks), media schedules (weekly publications, weekly television), financial markets (trading weeks), and religious practice (the Sabbath, Friday prayers, Sunday services).
Unlike the second, minute, hour, day, and year, the week has no physical basis — it is purely a social convention. Attempts to change it have consistently failed: the French Revolutionary calendar tried a 10-day "decade" (1793–1805) and was abandoned; the Soviet Union tried both 5-day and 6-day weeks (1929–1940) before reverting. The week's social utility — the predictable rhythm of work and rest — has proven more resilient than any political or mathematical reform.
The day is the approximate period of one rotation of the Earth on its axis relative to the Sun, equal to 24 hours or 86,400 seconds. More precisely, the solar day (from noon to noon) averages 24 hours over a year, while the sidereal day (one full rotation relative to fixed stars) is about 23 hours, 56 minutes, and 4 seconds. The difference arises because Earth is also orbiting the Sun, requiring a slightly longer rotation to bring the Sun back to the same position in the sky.
The day is the most fundamental natural unit of time for human biology and culture. Circadian rhythms — the internal biological clock that regulates sleep, hormone release, metabolism, and temperature — are synchronized to the 24-hour day by light signals through the eyes. Jet lag occurs when travel across time zones disrupts this synchronization. The day structures human activity so universally that "daily" is a synonym for "routine" in many languages.
In astronomy, the day is used to measure rotation periods of other planets and moons. Mars has a day (called a "sol") of about 24 hours and 37 minutes — close enough to Earth's that Mars rovers follow a Martian sol schedule. Venus rotates so slowly its day is longer than its year. The day is also the base unit for expressing orbital periods: Earth's Moon takes about 27.3 days to orbit Earth, and Jupiter takes about 4,333 days (11.9 years) to orbit the Sun.
1 Week equals 7 Days.
To convert Weeks to Days, multiply by 7. For example, 1 Week = 7 Days.
1 Day equals 0.142857 Weeks.