# xarray.core.accessor_dt.DatetimeAccessor.calendar

#### *property* DatetimeAccessor.calendar

The name of the calendar of the dates.

Only relevant for arrays of [`cftime.datetime`](https://unidata.github.io/cftime/api.html#cftime.datetime) objects,
returns “proleptic_gregorian” for arrays of [`numpy.datetime64`](https://numpy.org/doc/stable/reference/arrays.scalars.html#numpy.datetime64) values.