fix(datetime): discard unconfirmed selection on cancel

[ShaneK]

Issue number: resolves #30777, resolves #27975

---

What is the current behavior?

Currently, when ion-datetime is inside a modal or popover (usually through ion-datetime-button), cancelling or dismissing the overlay leaves the unconfirmed selection in place. The cancel() method only emits ionCancel and closes the overlay, so reopening the datetime shows the cancelled date as selected even though value never changed.

What is the new behavior?

The datetime now listens for its parent overlay's dismiss event and resets its selection to value unless the overlay was dismissed with the datetime-confirm role. That covers the Cancel button, backdrop taps, swipes and hardware back. The reset skips the month animation since the overlay has already animated out, otherwise cancelling a selection in another month left the calendar stuck on that month when reopened. Calling cancel() on an inline datetime now restores the committed selection right away.

Does this introduce a breaking change?

• Yes
• No

Other information

There was an earlier attempt at this in #27976 that called reset() from cancel(), which was closed until the design was settled. This reprocesses value directly instead, so it doesn't pick up the clearing behavior of reset().

This changes behavior in a few edge cases:

• Calling cancel() without closing an overlay now resets the selection, where before it only emitted ionCancel.
• If canDismiss blocks the dismiss, the selection stays, since the user is still in the picker.
• Apps that dismiss with a custom role and then call confirm() from their own onDidDismiss handler will confirm the original value, because the datetime resets first. Calling confirm(true), or confirm() before dismissing, isn't affected.

Use the "Popover - Custom" and "Modal - Custom" examples, pick a date, cancel, then reopen:

• Relevant test screen (iOS)
• Relevant test screen (MD)

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated
ionic-framework	Ready	Preview	Oct 9, 2026 12:52pm UTC

[thetaPC]

LGTM!