# datePickerCell(_:validateProposedDateValue:timeInterval:) The delegate receives this message each time the user attempts to change the receiver’s value, allowing the delegate the opportunity to override the change. ``` @MainActor optional func datePickerCell(_ datePickerCell: NSDatePickerCell, validateProposedDateValue proposedDateValue: AutoreleasingUnsafeMutablePointer, timeInterval proposedTimeInterval: UnsafeMutablePointer?) ``` ## Parameters `datePickerCell` The cell that sent the message. `proposedDateValue` On input, contains the proposed new date. The delegate may change this value before returning. `proposedTimeInterval` On input, contains the proposed new time interval. The delegate may change this value before returning. ## Discussion When returning a new `proposedDateValue`, the `NSDate` instance should be autoreleased, and the `proposedDateValue` should not be released by the delegate. The `proposedDateValue` and `proposedTimeInterval` are guaranteed to lie between the dates returned by [`minDate`](/documentation/AppKit/NSDatePickerCell/minDate) and [`maxDate`](/documentation/AppKit/NSDatePickerCell/maxDate). If you modify these values, you should ensure that the new values are within the appropriate range. --- 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)