Instance Method

ordinality(of:in:for:)

iOS 8.0+ iPadOS 8.0+ Mac Catalyst 8.0+ macOS 10.10+ tvOS 9.0+ watchOS 2.0+

Returns, for a given absolute time, the ordinal number of a smaller calendar component (such as a day) within a specified larger calendar component (such as a week).

func ordinality(of smaller: Calendar.Component, in larger: Calendar.Component, for date: Date) -> Int?

Parameters

smaller: The smaller calendar component.
larger: The larger calendar component.
date: The absolute time for which the calculation is performed.

Return Value

The ordinal number of smaller within larger at the time specified by date. Returns nil if larger is not logically bigger than smaller in the calendar, or the given combination of components does not make sense (or is a computation which is undefined).

Discussion

The ordinality is in most cases not the same as the decomposed value of the component. Typically return values are 1 and greater. For example, the time 00:45 is in the first hour of the day, and for components hour and day respectively, the result would be 1. An exception is the week-in-month calculation, which returns 0 for days before the first week in the month containing the date.

Note

Some computations can take a relatively long time.