## 1.52.14 calendar

    set calendar [ ( input | output ) ] <calendar>

The `set calendar` command sets the calendar that Pyxplot uses to convert dates between calendar dates and Julian Day numbers. Pyxplot uses two separate calendars which may be different: an input calendar for processing dates that the user inputs as calendar dates, and an output calendar that controls how dates are displayed or written on plots. The available calendars are `British`, `French`, `Greek`, `Gregorian`, `Hebrew`, `Islamic`, `Jewish`, `Julian`, `Muslim`, `Papal` and `Russian`, where `Jewish` is an alias for `Hebrew` and `Muslim` is an alias for `Islamic`.