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Coptic and Ethoiopic calendar dates

Source: R/coptic.R
coptic.Rd

These two calendars are identical apart from the starting point or epoch. The Coptic calendar (also called the Alexandrian calendar) starts on 29 August 284 CE in the Julian calendar, while the Ethiopic (or Ethiopian) calendar starts on 29 August 8 CE in the Julian calendar. The Coptic calendar is used by the Coptic Orthodox and Coptic Catholic Churches, while the Ethiopic calendar is the official state calendar of Ethiopia, and unofficial calendar of Eritrea, and is used by the Ethiopian and Eritrean Orthodox Churches. Both calendars have 13 months, with 12 months of 30 days and a 13th month of 5 or 6 days depending on whether it is a leap year. Leap years occur every 4 years.

Usage

coptic_date(year = integer(), month = integer(), day = integer())

ethiopic_date(year = integer(), month = integer(), day = integer())

as_coptic(date)

as_ethiopic(date)

Arguments

year

A numeric vector of years

month

A numeric vector of months

day

A numeric vector of days

date

A numeric vector of dates

Value

A coptic or ethiopic vector object

See also

cal_coptic, cal_ethiopic, coptic_christmas

Examples

tibble::tibble(
  gregorian = gregorian_date(2025, 1, 1:31),
  coptic = as_coptic(gregorian),
  ethiopic = as_ethiopic(gregorian)
)
#> # A tibble: 31 × 3
#>      gregorian      coptic     ethiopic
#>          <Gre>       <Cop>        <Eth>
#>  1 2025-Jan-01 1741-Koi-23 2017-Takh-23
#>  2 2025-Jan-02 1741-Koi-24 2017-Takh-24
#>  3 2025-Jan-03 1741-Koi-25 2017-Takh-25
#>  4 2025-Jan-04 1741-Koi-26 2017-Takh-26
#>  5 2025-Jan-05 1741-Koi-27 2017-Takh-27
#>  6 2025-Jan-06 1741-Koi-28 2017-Takh-28
#>  7 2025-Jan-07 1741-Koi-29 2017-Takh-29
#>  8 2025-Jan-08 1741-Koi-30 2017-Takh-30
#>  9 2025-Jan-09 1741-Tob-01  2017-Ter-01
#> 10 2025-Jan-10 1741-Tob-02  2017-Ter-02
#> # ℹ 21 more rows
coptic_date(1741, 5, 16:18)
#> <coptic[3]>
#> [1] 1741-Tob-16 1741-Tob-17 1741-Tob-18
as_date(Sys.Date(), calendar = cal_ethiopic)
#> <ethiopic[1]>
#> [1] 2017-Ham-15
as_coptic("2016-01-01")
#> <coptic[1]>
#> [1] 1732-Koi-22
as_ethiopic(Sys.Date())
#> <ethiopic[1]>
#> [1] 2017-Ham-15