feat(events): autofill and bound End Date from Start Date

[harshtandiya]

Picking a Start Date on Buzz Event left End Date entirely on the user, and nothing stopped them from putting it before the start. The server caught that on save via validate_from_to_dates, but only after a full round trip.

Three small things in buzz_event.js:

• Start Date fills an empty End Date with the same value. Non-empty End Date is left alone.
• If the new Start Date is past the existing End Date, End Date is pulled forward to match and an alert says so. Silently saving an invalid range was the alternative.
• The End Date picker gets a minDate, so earlier dates aren't offered in the first place.

Gotchas worth knowing:

min_date on the docfield is only read once, when the control builds its picker — set_df_property does nothing after that. The limit has to go onto the datepicker instance directly (field.datepicker.update({ minDate })), same as frappe/form/reminders.js does. Hence the set_end_date_limit helper, called from both refresh and start_date.

minDate is inclusive, so end == start is still allowed. It has to be — single-day events are the common case and the autofill produces exactly that.

Dates are YYYY-MM-DD strings, so the < comparison is chronological. No date lib needed.

Not changed:

• No new server-side validation. validate_dates already calls validate_from_to_dates("start_date", "end_date"); this is a UX layer on top, not a replacement.
• validate_schedule untouched. Pulling End Date forward can now strand schedule rows past it — the server already throws on those, which is the right place for it.

Desk-only change, no dashboard impact.

[greptile-apps]

Greptile Summary

Adds client-side handling that synchronizes and bounds an event’s End Date when its Start Date changes.

• Autofills an empty End Date from the selected Start Date.
• Moves an earlier End Date forward and displays an alert.
• Applies an inclusive minimum date directly to the End Date picker on refresh and Start Date changes.

Confidence Score: 5/5

The PR appears safe to merge, with no concrete changed-code failure identified.

The new handler preserves existing non-empty valid End Dates, corrects invalid ranges, and refreshes the picker constraint while retaining server-side validation.

Important Files Changed

Filename	Overview
buzz/events/doctype/buzz_event/buzz_event.js	Adds Start Date-driven End Date synchronization and updates the End Date picker’s minimum selectable date; no concrete defect was established.

_{Reviews (1): Last reviewed commit: "feat(events): autofill and bound End Dat..." | Re-trigger Greptile}

[github-actions]

Successfully created backport PR for main:

• feat(events): autofill and bound End Date from Start Date #316