Module calendrica-islamic
Islamic calendar conversions and holidays.
Ported from "Calendrical Calculations" (4th edition) by Nachum Dershowitz and Edward M. Reingold. Original Lisp code (CALENDRICA 4.0) is Apache 2.0 licensed.
Info:
- Release: 0.1 2026-07-19
Functions
| islamic_date (year, month, day) | Construct an Islamic date {year, month, day}. |
| fixed_from_islamic (i_date) | Fixed date equivalent to Islamic date `i_date`. |
| islamic_from_fixed (date) | Islamic date {year, month, day} corresponding to fixed `date`. |
| fixed_from_islamic_tbla (i_date) | Fixed date equivalent to Islamic TBLA date `i_date`. |
| islamic_tbla_from_fixed (date) | Islamic TBLA date {year, month, day} corresponding to fixed `date`. |
| fixed_from_islamic_umalqura (i_date) | Fixed date equivalent to Umm al-Qura Islamic date `i_date`. |
| islamic_umalqura_from_fixed (date) | Umm al-Qura Islamic date {year, month, day} corresponding to fixed `date`. |
| ramadan (g_year) | Fixed dates of Ramadan start (month 9, day 1) in Gregorian year `g_year`. |
| eid_al_fitr (g_year) | Fixed dates of Eid al-Fitr (month 10, day 1) in Gregorian year `g_year`. |
| eid_al_adha (g_year) | Fixed dates of Eid al-Adha (month 12, day 10) in Gregorian year `g_year`. |
| islamic_new_year (g_year) | Fixed dates of Islamic New Year (Muharram 1) occurring in Gregorian year `g_year`. |
| mawlid (g_year) | Fixed dates of Mawlid an-Nabi occurring in Gregorian year `g_year`. |
| islamic_in_gregorian (i_month, i_day, g_year) | Fixed dates of Islamic month/day `i_month`/`i_day` falling in Gregorian year `g_year`. |
| islamic_leap_year (i_year) | True if Islamic year `i_year` is a leap year (355 days). |
Fields
| ISLAMIC_EPOCH | Fixed date of start of the Islamic calendar (July 16, 622 CE Julian). |
| ISLAMIC_EPOCH_TBLA | Fixed date of start of the Islamic TBLA calendar (July 15, 622 CE Julian). |
Functions
- islamic_date (year, month, day)
-
Construct an Islamic date {year, month, day}.
Parameters:
- year number Islamic year.
- month number Islamic month.
- day number Islamic day.
Returns:
-
table
{year, month, day}
- fixed_from_islamic (i_date)
-
Fixed date equivalent to Islamic date `i_date`.
Parameters:
- i_date table Islamic date {year, month, day}.
Returns:
-
number
Fixed date.
- islamic_from_fixed (date)
-
Islamic date {year, month, day} corresponding to fixed `date`.
Parameters:
- date number Fixed date.
Returns:
-
table
{year, month, day}
- fixed_from_islamic_tbla (i_date)
-
Fixed date equivalent to Islamic TBLA date `i_date`.
Identical to the civil calendar but uses the Thursday epoch (one day earlier).
Parameters:
- i_date table Islamic date {year, month, day}.
Returns:
-
number
Fixed date.
- islamic_tbla_from_fixed (date)
-
Islamic TBLA date {year, month, day} corresponding to fixed `date`.
Parameters:
- date number Fixed date.
Returns:
-
table
{year, month, day}
- fixed_from_islamic_umalqura (i_date)
-
Fixed date equivalent to Umm al-Qura Islamic date `i_date`.
Parameters:
- i_date table Islamic date {year, month, day}.
Returns:
-
number
Fixed date.
- islamic_umalqura_from_fixed (date)
-
Umm al-Qura Islamic date {year, month, day} corresponding to fixed `date`.
Parameters:
- date number Fixed date.
Returns:
-
table
{year, month, day}
- ramadan (g_year)
-
Fixed dates of Ramadan start (month 9, day 1) in Gregorian year `g_year`.
Parameters:
- g_year number Gregorian year.
Returns:
-
{number,...}
Fixed dates.
- eid_al_fitr (g_year)
-
Fixed dates of Eid al-Fitr (month 10, day 1) in Gregorian year `g_year`.
Parameters:
- g_year number Gregorian year.
Returns:
-
{number,...}
Fixed dates.
- eid_al_adha (g_year)
-
Fixed dates of Eid al-Adha (month 12, day 10) in Gregorian year `g_year`.
Parameters:
- g_year number Gregorian year.
Returns:
-
{number,...}
Fixed dates.
- islamic_new_year (g_year)
-
Fixed dates of Islamic New Year (Muharram 1) occurring in Gregorian year `g_year`.
Parameters:
- g_year number Gregorian year.
Returns:
-
{number,...}
Fixed dates.
- mawlid (g_year)
-
Fixed dates of Mawlid an-Nabi occurring in Gregorian year `g_year`.
Parameters:
- g_year number Gregorian year.
Returns:
-
table
List of fixed dates.
- islamic_in_gregorian (i_month, i_day, g_year)
-
Fixed dates of Islamic month/day `i_month`/`i_day` falling in Gregorian year `g_year`.
Parameters:
- i_month number Islamic month.
- i_day number Islamic day.
- g_year number Gregorian year.
Returns:
-
{number,...}
Fixed dates.
- islamic_leap_year (i_year)
-
True if Islamic year `i_year` is a leap year (355 days).
Parameters:
- i_year number Islamic year.
Returns:
-
boolean