&reftitle.constants; &extension.constants;

`CAL_EASTER_DEFAULT` (`int`)

- For `easter_days`: calculate Easter for years before 1753 according to the Julian calendar, and for later years according to the Gregorian calendar.

`CAL_EASTER_ROMAN` (`int`)

- For `easter_days`: calculate Easter for years before 1583 according to the Julian calendar, and for later years according to the Gregorian calendar.

`CAL_EASTER_ALWAYS_GREGORIAN` (`int`)

- For `easter_days`: calculate Easter according to the proleptic Gregorian calendar.

`CAL_EASTER_ALWAYS_JULIAN` (`int`)

- For `easter_days`: calculate Easter according to the Julian calendar.

`CAL_GREGORIAN` (`int`)

- For `cal_days_in_month`, `cal_from_jd`, `cal_info` and `cal_to_jd`: use the proleptic Gregorian calendar.

`CAL_JULIAN` (`int`)

- For `cal_days_in_month`, `cal_from_jd`, `cal_info` and `cal_to_jd`: use the Julian calendar.

`CAL_JEWISH` (`int`)

- For `cal_days_in_month`, `cal_from_jd`, `cal_info` and `cal_to_jd`: use the Jewish calendar.

`CAL_FRENCH` (`int`)

- For `cal_days_in_month`, `cal_from_jd`, `cal_info` and `cal_to_jd`: use the French Repuclican calendar.

`CAL_NUM_CALS` (`int`)

- The number of available calendars.

`CAL_JEWISH_ADD_ALAFIM_GERESH` (`int`)

- For `jdtojewish`: adds a geresh symbol (which resembles a single-quote mark) as thousands separator to the year number.

`CAL_JEWISH_ADD_ALAFIM` (`int`)

- For `jdtojewish`: adds the word alafim as thousands separator to the year number.

`CAL_JEWISH_ADD_GERESHAYIM` (`int`)

- For `jdtojewish`: add a gershayim symbol (which resembles a double-quote mark) before the final letter of the day and year numbers.

`CAL_DOW_DAYNO` (`int`)

- For `jddayofweek`: the day of the week as `int`, where `0` means Sunday and `6` means Saturday.

`CAL_DOW_SHORT` (`int`)

- For `jddayofweek`: the abbreviated English name of the day of the week.

`CAL_DOW_LONG` (`int`)

- For `jddayofweek`: the English name of the day of the week.

`CAL_MONTH_GREGORIAN_SHORT` (`int`)

- For `jdmonthname`: the abbreviated Gregorian month name.

`CAL_MONTH_GREGORIAN_LONG` (`int`)

- For `jdmonthname`: the Gregorian month name.

`CAL_MONTH_JULIAN_SHORT` (`int`)

- For `jdmonthname`: the abbreviated Julian month name.

`CAL_MONTH_JULIAN_LONG` (`int`)

- For `jdmonthname`: the Julian month name.

`CAL_MONTH_JEWISH` (`int`)

- For `jdmonthname`: the Jewish month name.

`CAL_MONTH_FRENCH` (`int`)

- For `jdmonthname`: the French Republican month name.