#### 4.3.2 `calendarDuration` Class ¶

A `calendarDuration` represents a period of time in variable-length calendar components. For example, years and months can have varying numbers of days, and days in time zones with Daylight Saving Time have varying numbers of hours. A `calendarDuration` does arithmetic with "whole" calendar periods.

`calendarDuration`s and `duration`s cannot be directly combined, because they are not semantically equivalent. (This may be relaxed in the future to allow `duration`s to be interpreted as numbers of days when combined with `calendarDuration`s.)

    d = datetime('2011-03-04 00:00:00')
        ⇒ 04-Mar-2011
    cdur = calendarDuration(1, 3, 0)
        ⇒ 1y 3mo
    d2 = d + cdur
        ⇒ 04-Jun-2012