You check a listing you'd bookmarked from last week — a farm's fall festival, say — and the page is gone. Not "closed for the season," just gone: a 404, or a domain that suddenly points somewhere else entirely. Your first instinct is to pull the event. No page, no event, simple.
I've made that call and been wrong. The festival was still happening. The farm had switched to a new website the same week, and every old link broke at once. Nothing about the event had changed. The page had just moved out from under it.
By the time we caught it, the listing had already been off the calendar for a few days. Nobody complained, because nobody who would have complained knew the listing had existed in the first place. That's what made it worse, not better: the mistake didn't announce itself. It just made a real event a little quieter than it should have been, right when people were deciding what to do that weekend.
1. What does a missing page actually tell you?
On its own, not much. A 404 can mean the event was cancelled and the organizer took the page down on purpose. It can also mean a site migration, an expired domain, a redesign that dropped the old URL structure, or a temporary outage that resolves itself by morning. All of those look identical from the outside: a link that used to work and now doesn't.
Treating every version of that as "cancelled" is the easy answer, and it's wrong often enough to matter. Someone plans their Saturday around a listing being on the calendar. If we pull it because a link broke, rather than because the event actually ended, we've turned a technical problem into a wrong answer for a family that trusted the calendar.
2. What do you check before you believe it?
A missing page is a question, not an answer. Before anything comes off a calendar, we look for other signs of what actually happened. Does the organizer's site still exist somewhere, just at a different address? Does the event show up anywhere else the organizer controls? Has anything else about that organizer changed recently, or is this an isolated broken link with nothing else different?
If those checks point to the event genuinely being over, it comes down, and that's the right outcome. If they point to something having moved, we follow it rather than erase it. And if we can't tell yet, the honest answer is to hold the listing and keep looking rather than guess in either direction.
None of that is exotic. It's closer to what you'd do yourself if a friend's website suddenly 404'd: you wouldn't assume they'd closed up shop. You'd ask around, check if they mentioned anything, maybe try the site again the next day before concluding anything. The only difference is doing that consistently, for every broken link, instead of only for the ones you happen to notice.
3. What's the cost of guessing wrong?
Guess "still on" when it's actually cancelled, and someone shows up to a locked gate. Guess "cancelled" when it's actually still on, and a real event quietly disappears from every calendar that trusted the wrong signal, while the organizer never finds out why their attendance dropped. Neither mistake is loud. Both are the kind you only notice much later, if you notice at all.
That's the part that stuck with me. A wrong price or a typo gets caught fast, because someone notices immediately. A wrong cancellation just makes an event a little less visible, indefinitely, with no error message anywhere for anyone to find.
Why this matters if you rely on local data
A calendar is only useful if "off the calendar" reliably means "actually not happening." That's a small promise, and it only holds if the system resists the temptation to treat every broken link as a cancellation. The alternative — moving fast and occasionally erasing something real — costs someone a Saturday, and costs an organizer a listing they didn't know they'd lost.