| Utils | Some utilities. |
| Time_Zone | Time zone management. |
| Period | A period represents the time passed between two events (a date, a time...). |
| Time_sig | Time interface. |
| Time | Time implementation in which seconds are integers. |
| Ftime | Time implementation in which seconds are floats. |
| Date_sig | Date interface. |
| Date | Date implementation. |
| Calendar_sig | Calendar interface. |
| Calendar_builder | Generic calendar implementation. |
| Calendar | Calendar implementation in which seconds are integer. |
| Fcalendar | Calendar implementation in which seconds are float. |
| Printer | Pretty printing and parsing from string. |
| Version | Information about version of calendar. |