| Christian | Day Count | French Republic | General Hybrid | Gregorian | Hebrew |
| Islamic | Julian | Regional | |||
| Code | Name | Description |
|---|---|---|
| Christian | ||
| jlit | Julian Liturgical | The Christian Liturgical calendar based on the Julian calendar. |
| glit | Gregorian Liturgical | The Christian Liturgical calendar based on the Gregorian calendar. |
| Day Count | ||
| 7 Day Week | The cyclic 7 day week. Not an independent calendar but often used in conjunction with others. | |
| jdn | Julian Day Number | The internal date representation used by HistoryCal. A minor variation of the "Julian Day". |
| jd | Julian Day | The day count used by astronomers, also known as Julian Astronomical Day. |
| Julian | ||
| j | Julian | The simplest version of the Julian calendar, includes year zero. As used in astronomy. |
| jce | Julian Common Era | A version of the Julian calendar commonly used by historians. Year is marked as BCE or CE. |
| jn | Julian Nativity | A Julian calendar with the year change on the preceding 25th December. |
| ja | Julian Annunciation | A Julian calendar with the year change on the 25th March, calculus florentinus. |
| jap | Julian Annunciation Pisa | A Julian calendar with the year change on the preceding 25th March, calculus pisanus. |
| se | Julian Spanish Era | A Julian calendar with the epoch of 1st January -37. |
| Gregorian | ||
| g | Gregorian | The Gregorian calendar. |
| gce | Gregorian Common Era | A version of the Gregorian calendar sometimes used by historians. Year is marked as BCE or CE. |
| isow | ISO Week | The ISO:8601 Year, Week number and Day of week calendar. |
| isoo | ISO Ordinal | The ISO:8601 Year and Day number calendar. |
| General Hybrid | ||
| ay | Astronomical Year | The Astronomical Year calendar. |
| ce | Common Era | A universal calendar convenent for use by historians. Year is marked as BCE or CE. |
| French Republic | ||
| fr | French Republican | An astronomical calendar introduced after the French Revolution. |
| Hebrew | ||
| h | Hebrew | Hebrew Arithmetical calendar. |
| Islamic | ||
| i | Islamic Tabular | Islamic tabular calendar. |
| ims | Islamic Microsoft Hijri | Islamic Microsoft Hijri calendar. |
| if | Islamic Fātimid | Islamic Fātimid calendar. |
| Regional | ||
| cath | Catholic Hybrid | Hybrid calendar used in regions that changed from Julian to Gregorian on 15th October 1582. |
| eng | English Hybrid | The calendar as used in England and English colonies. |
| er | English Regnal | The English and British Regnal calendar from Henry II to present day. |
| scot | Scottish Hybrid | The calendar as used in Scotland. |
| sr | Scottish Regnal | The Scottish and British Regnal calendar to present day. |
| swed | Swedish Hybrid | The calendar used by Sweden when changing from Julian to Gregorian.. |
