Description
Calendrical Calculations.
Description
An R implementation of the algorithms described in Reingold and Dershowitz (4th ed., Cambridge University Press, 2018) <doi:10.1017/9781107415058>, allowing conversion between many different calendar systems. Cultural and religious holidays from several calendars can be calculated.
README.md
calcal 
The goal of calcal is to do calendrical calculations, based on the algorithms described in Reingold and Dershowitz (2018) Calendrical Calculations, 4th edition, Cambridge University Press.
It is largely a translation of the Lisp code produced by Reingold and Dershowitz for Calendrica 4.0.
Installation
You can install the stable version from CRAN with:
pak::pak("calcal")
You can install the development version from GitHub with:
pak::pak("robjhyndman/calcal")
Example
Dates in multiple calendars:
library(calcal)
library(tibble)
library(tidyr)
library(dplyr)
tibble(
Gregorian = gregorian_date(1990, 2, 20) + 1:10,
ISO = as_iso(Gregorian),
Islamic = as_islamic(Gregorian),
Hebrew = as_hebrew(Gregorian)
)
#> # A tibble: 10 × 4
#> Gregorian ISO Islamic Hebrew
#> <Gre> <ISO> <Hij> <Heb>
#> 1 1990-Feb-21 1990-08-03 1410-Raj-25 5750-Shevat-26
#> 2 1990-Feb-22 1990-08-04 1410-Raj-26 5750-Shevat-27
#> 3 1990-Feb-23 1990-08-05 1410-Raj-27 5750-Shevat-28
#> 4 1990-Feb-24 1990-08-06 1410-Raj-28 5750-Shevat-29
#> 5 1990-Feb-25 1990-08-07 1410-Raj-29 5750-Shevat-30
#> 6 1990-Feb-26 1990-09-01 1410-Raj-30 5750-Adar-01
#> 7 1990-Feb-27 1990-09-02 1410-Sha-01 5750-Adar-02
#> 8 1990-Feb-28 1990-09-03 1410-Sha-02 5750-Adar-03
#> 9 1990-Mar-01 1990-09-04 1410-Sha-03 5750-Adar-04
#> 10 1990-Mar-02 1990-09-05 1410-Sha-04 5750-Adar-05
Some religious and cultural holidays
tibble(
year = 2025:2028,
# Christian holidays
Easter = easter(year),
`Orthodox Easter` = orthodox_easter(year),
Christmas = christmas(year),
`Orthodox Christmas` = orthodox_christmas(year),
# Jewish holidays
`Rosh Hashanah` = rosh_hashanah(year),
Passover = passover(year),
`Yom Kippur` = yom_kippur(year),
Sukkot = sukkot(year),
Hanukkah = hanukkah(year),
# Islamic holidays
Ramadan = ramadan(year),
`Eid al-Fitr` = eid_al_fitr(year),
`Eid al-Adha` = eid_al_adha(year),
# Chinese Holidays
`Chinese New Year` = chinese_new_year(year),
`Dragon Festival` = dragon_festival(year),
`Qing Ming` = qing_ming(year),
# Hindu Holidays
`Hindu Lunar New Year` = hindu_lunar_new_year(year),
`Hindu Solar New Year` = mesha_sankranti(year),
Diwali = diwali(year),
Rama = rama(year),
Shiva = shiva(year)
) |>
pivot_longer(-year) |>
pivot_wider(names_from = year, values_from = value) |>
arrange(`2025`)
#> # A tibble: 20 × 5
#> name `2025` `2026` `2027` `2028`
#> <chr> <Gre> <Gre> <Gre> <Gre>
#> 1 Orthodox Christmas 2025-Jan-07 2026-Jan-07 2027-Jan-07 2028-Jan-07
#> 2 Chinese New Year 2025-Jan-29 2026-Feb-17 2027-Feb-06 2028-Jan-26
#> 3 Shiva 2025-Feb-27 2026-Feb-16 2027-Mar-07 2028-Feb-24
#> 4 Ramadan 2025-Mar-01 2026-Feb-18 2027-Feb-08 2028-Jan-28
#> 5 Hindu Lunar New Year 2025-Mar-30 2026-Mar-19 2027-Apr-07 2028-Mar-27
#> 6 Eid al-Fitr 2025-Mar-31 2026-Mar-20 2027-Mar-10 2028-Feb-27
#> 7 Qing Ming 2025-Apr-04 2026-Apr-05 2027-Apr-05 2028-Apr-04
#> 8 Rama 2025-Apr-06 2026-Mar-27 2027-Apr-15 2028-Apr-04
#> 9 Passover 2025-Apr-13 2026-Apr-02 2027-Apr-22 2028-Apr-11
#> 10 Hindu Solar New Year 2025-Apr-14 2026-Apr-14 2027-Apr-14 2028-Apr-13
#> 11 Easter 2025-Apr-20 2026-Apr-05 2027-Mar-28 2028-Apr-16
#> 12 Orthodox Easter 2025-Apr-20 2026-Apr-12 2027-May-02 2028-Apr-16
#> 13 Dragon Festival 2025-May-31 2026-Jun-19 2027-Jun-09 2028-May-28
#> 14 Eid al-Adha 2025-Jun-07 2026-May-27 2027-May-17 2028-May-05
#> 15 Rosh Hashanah 2025-Sep-23 2026-Sep-12 2027-Oct-02 2028-Sep-21
#> 16 Yom Kippur 2025-Oct-02 2026-Sep-21 2027-Oct-11 2028-Sep-30
#> 17 Sukkot 2025-Oct-07 2026-Sep-26 2027-Oct-16 2028-Oct-05
#> 18 Diwali 2025-Oct-22 2026-Nov-10 2027-Oct-30 2028-Nov-17
#> 19 Hanukkah 2025-Dec-15 2026-Dec-05 2027-Dec-25 2028-Dec-13
#> 20 Christmas 2025-Dec-25 2026-Dec-25 2027-Dec-25 2028-Dec-25