# ordinality(of:in:for:) Returns, for a given absolute time, the ordinal number of a smaller calendar unit (such as a day) within a specified larger calendar unit (such as a week). ``` func ordinality(of smaller: NSCalendar.Unit, in larger: NSCalendar.Unit, for date: Date) -> Int ``` ## Parameters `smaller` The smaller calendar unit `larger` The larger calendar unit `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 `NSNotFound` if `larger` is not logically bigger than `smaller` in the calendar, or the given combination of units 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 unit. Typically return values are `1` and greater. For example, the time `00:45` is in the first hour of the day, and for units 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 that some computations can take a relatively long time. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)