Indictions to Days (indiction to d)
1 indiction equals 5,478.6375 days exactly.
How to convert indictions to days
To convert indictions to days, multiply the number of indictions by 5,478.6375. This factor is exact. To go the other way, multiply days by 0.0001825271338 (rounded).
days = indictions × 5,478.6375
Example: 10 indictions = 54,786.375 days.
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.
About these units
Indiction (indiction)
A 15-year tax cycle introduced under the Roman Empire and used to date documents in the Byzantine and medieval worlds.
Indictions began as periodic reassessments of land or poll taxes in the Roman Empire, and the Latin indictio means an imposition or levy. Evidence exists for a 15-year cycle across the empire, a 14-year cycle in Roman Egypt, and a five-year cycle. Tax changes and arrears remissions tended to fall at the start of a cycle, with examples recorded under Nero in 58 AD and Hadrian in 118 AD.
Constantine is credited with turning the 15-year cycle into a dating system in 312 AD, and Egypt used it by 314 AD, though sources disagree on the first year, with one Coptic document implying 297 to 298. Justinian required indictions in dated documents in 537 AD. The year began on 23 September in the early Eastern Empire, later moving to 1 September, while Bede gives 24 September for the West and papal practice started on 25 December or 1 January. Because the length is a convention of 15 years, the figure used here is 15 Gregorian years, about 473.4 million seconds. The cycle also forms part of the 7,980-year Julian Period.
1 indiction = 473,354,280 seconds (exactly).
Sources: Wikipedia: Indiction
Day (d)
24 hours or 86,400 seconds. The mean solar day; the actual rotation of the Earth is about 4 minutes shorter (see sidereal day).
Old English dæg is the root of our day, with close cousins in German Tag, Dutch dag and Icelandic dagur, all descending from Proto-Germanic dagaz. It is the oldest unit here, because the cycle of light and dark needs no instrument. Yet the day we count is a constructed average: the actual interval from one noon to the next varies through the year by up to about 7.9 seconds, because Earth's orbit is elliptical and its axis is tilted.
Astronomers smooth this out with a fictitious mean Sun, giving the mean solar day, and the day in the SI sense is fixed at exactly 86,400 seconds. Reality has drifted slightly: the mean solar day has recently averaged about 86,400.002 seconds, and tidal drag from the Moon is lengthening it by about 2 milliseconds per century. That is why 27 leap seconds were added to UTC between 1972 and 2022. One rotation measured against the distant stars is shorter, about 23 hours 56 minutes 4.09 seconds, and a year contains one more of these sidereal days than solar days.
1 day = 86,400 seconds (exactly).
Sources: Wikipedia: Day; BIPM: SI Brochure, 9th edition
Related conversions
- Days to indictions (reverse)
- Indictions to seconds
- Indictions to minutes
- Indictions to hours
- Indictions to weeks
- Indictions to months
- Indictions to years
- Seconds to days
- Minutes to days
- Hours to days
- Weeks to days
- Months to days
- Years to days
- Milliseconds to days
- Microseconds to days
- Nanoseconds to days
- Decades to days
- Centuries to days
- Millennia to days
See all time units.