Lightning had the ability to search the entire calendar for an event, sadly, this new iteration of the calendar built into Thunderbird 128.0.1esr doesn't support anything but today or later events. Most of the time I use the calendar to search for a previous event (when I was previously somewhere). This is very important and an oversight on the part of who thought the search from now until the end of time was all anyone would need. Can the functionality be returned to search every event and not just from today onward?