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This file contains important structs and functions relating to location, time, and astronomy; these are intended for calender calculations and based off Calendrical Calculations by Reingold & Dershowitz.
TODO(#3709): Address inconcistencies with existing ICU code for extreme dates.
Structs§
- Astronomical
- The Astronomical struct provides functions which support astronomical calculations used by many observational calendars.
- Location
- A Location on the Earth given as a latitude, longitude, elevation, and standard time zone. Latitude is given in degrees from -90 to 90, longitude in degrees from -180 to 180, elevation in meters, and zone as a UTC offset in fractional days (ex. UTC+1 would have zone = 1.0 / 24.0)
Constants§
- J2000
- The Moment of noon on January 1, 2000
- MAX_
UTC_ OFFSET - The maximum allowable UTC offset (+14 hours) in fractional days (14.0 / 24.0 days)
- MEAN_
SYNODIC_ MONTH - The mean synodic month in days of 86400 atomic seconds (86400 seconds = 24 hours * 60 minutes/hour * 60 seconds/minute)
- MEAN_
TROPICAL_ YEAR - The mean tropical year in days
- MECCA
- The location of Mecca; used for Islamic calendar calculations.
- MIN_
UTC_ OFFSET - The minimum allowable UTC offset (-12 hours) in fractional days (-0.5 days)
- NEW_
MOON_ ZERO - The moment of the first new moon of the CE, which occurred on January 11, 1 CE.
- WINTER
- The angle of winter for the purposes of solar calculations