# date(bySettingUnit:value:of:options:) Returns a new date representing the date calculated by setting a specific component of a given date to a given value, while trying to keep lower components the same. ``` func date(bySettingUnit unit: NSCalendar.Unit, value v: Int, of date: Date, options opts: NSCalendar.Options = []) -> Date? ``` ## Parameters `unit` The unit to set with the given value. For possible values, see [`NSCalendar.Unit`](/documentation/Foundation/NSCalendar/Unit). `v` The value to set for the given calendar unit. `date` The date to use to perform the calculation. `opts` Options for the calculation. For possible values, see [`NSCalendar.Options`](/documentation/Foundation/NSCalendar/Options). ## Return Value A new `NSDate` instance representing the date calculated by setting a specific component of a given date to a given value. If the unit already has that value, this may result in a date which is the same as the given date. If no such time exists for the specified components, the next available date is returned, which may be on a different calendar day. ## Discussion Changing a component’s value often requires higher or coupled components to change as well. For example, setting the `weekday` to “Thursday” will require the `day` component to change its value, and possibly the `month` and `year` as well. You can use the [`nextDate(after:matching:value:options:)`](/documentation/Foundation/NSCalendar/nextDate(after:matching:value:options:)) method to specify more precise behavior for determining the next or previous date for a given date component. ## See Also [`- nextDateAfterDate:matchingUnit:value:options:`](/documentation/Foundation/NSCalendar/nextDate(after:matching:value:options:)) Returns the next date after a given date matching the given calendar unit value. --- 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)