1772322 - All Day Event renders as 12:00AM-12:00AM, which is one day longer than event

Status: UNCONFIRMED

(Calendar :: General, defect)

Description

[Justin Zachor]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:101.0) Gecko/20100101 Firefox/101.0

Steps to reproduce:

In Calendar -- Add new event, and check "All day event". This changes from the settings preset (default 1-hour) time-span to 12:00AM-12:00AM. Save and close.

Actual results:

This renders as two days in both the calendar grid, and the list of upcoming events; if the dates are chosen as multi-day N, then render is N+1.
Time span was set to 12:00AM-12:00AM (rather than 12:00AM-11:59PM).
Also, when the event is edited, the end date is now shown as one more than what was set when the event was created. If the dates are corrected, saving still uses 12:00AM-12:00AM, so it again increments the # of days.
Also, if the "All day event" box is changed to unchecked, the time-span returns to the preference setting (default of 1 hour), but the end-date remains N+1.
NOTE ALSO: With All-day-event checked, unable to manually adjust the end-time to 11:59PM; If All-day-event is unchecked and the start/end times are set 12:00AM-11:59PM, then the event is shown on the calendar with a start time, rather than without, as is the style for all day events.

Expected results:

This should have rendered as one day, vs two (or N days vs N+1.)
Time span should have been set to (rendered as) 12:00AM-11:59PM.
ALSO, when the event is edited and All-day-event is unchecked, Calendar should have maintained the original date span (number of days) rather than incrementing by one.

Comment 1

[Martin Schröder [:mschroeder]]

Justin, have you tried Thunderbird 115 and do you still experience this issue?