Weeks to Tropical Years (wk to yr (trop))
1 week equals 0.01916536532 tropical years (rounded).
How to convert weeks to tropical years
To convert weeks to tropical years, multiply the number of weeks by 0.01916536532. The factor is rounded to 10 significant digits. To go the other way, multiply tropical years by 52.17745571 (rounded).
tropical years = weeks × 0.01916536532
Example: 10 weeks = 0.1916536532 tropical years.
Months and years are not constant. This site uses the average Gregorian year of 365.2425 days, so one 'year' converts to 365.2425 days, not 365; use 'common year' for exactly 365 days.
Approximate value. Standards for the tropical year varied by place and period, so this converter uses the most commonly cited value. Treat results as estimates, not exact figures.
About these units
Week (wk)
Seven days. The seven-day week comes from the ancient Near East and is nearly universal in the modern calendar.
Nothing in the sky produces a seven-day cycle, which makes the week a human invention with a contested pedigree. Babylonians marked the 7th, 14th, 21st and 28th of the lunar month as special, but that was not a continuous cycle. A continuous seven-day cycle tied to the Sabbath is attested in Judaism by the 6th century BC at the latest, and scholars disagree on whether it was borrowed from Babylon or developed independently. The Romans later used a week named for the Sun, the Moon and the five visible planets, and in AD 321 Emperor Constantine decreed it across the empire.
A week is seven days, or 604,800 seconds, and it divides evenly into neither months nor years, which is why calendars shift against it. The ISO 8601 standard starts each week on Monday and assigns week 1 to the week containing the year's first Thursday, so some years have a week 53. Other societies used different lengths: Rome had an eight-day market cycle, and revolutionary France used a ten-day week from 1793 to 1802. The English word comes from Old English wice, meaning a turn or succession.
1 week = 604,800 seconds (exactly).
Sources: Wikipedia: Week; Wikipedia: ISO week date
Tropical Year (yr (trop))
About 365.24219 days, the time between successive spring equinoxes. The Gregorian calendar approximates it.
Tropical comes from a Greek word meaning turning, and this year is measured by the cycle of the seasons: the time for the Sun to return to the same ecliptic longitude. The mean value at the start of 2000 was 365.2421897 days, or 365 days 5 hours 48 minutes 45.19 seconds. Individual intervals between March equinoxes wander by minutes, so the mean is what is normally quoted.
Hipparchus timed equinoxes in the second century BC and arrived at 365 days 5 hours 55 minutes 12 seconds, a little long. The Alfonsine Tables of 1252 gave 365 days 5 hours 49 minutes 16 seconds, and this value guided the Gregorian reform of 1582, which was needed because the equinox had slipped about ten days from its date at the Council of Nicaea in 325.
Kepler's Rudolphine Tables of 1627 came within a second or so of the modern figure, and Simon Newcomb's 1898 value of about 365.24219878 days served the national almanacs until 1983. The Gregorian calendar averages 365.2425 days, which tracks the tropical year closely.
1 tropical year = 31,556,925.22 seconds (approximately).
Sources: Wikipedia: Tropical year; NASA Earth Fact Sheet
Related conversions
- Tropical years to weeks (reverse)
- Weeks to seconds
- Weeks to minutes
- Weeks to hours
- Weeks to days
- Weeks to months
- Weeks to years
- Weeks to milliseconds
- Weeks to microseconds
- Weeks to nanoseconds
- Weeks to decades
- Weeks to centuries
- Weeks to millennia
- Seconds to tropical years
- Minutes to tropical years
- Hours to tropical years
- Days to tropical years
- Months to tropical years
- Years to tropical years
See all time units.