The cost of being wrong is not abstract

A blog with a wrong date has a typo. A venue with a wrong date has an empty room on a Tuesday, a band who travelled, and a bar staffed for a crowd that went somewhere else. The calendar is the only part of the website with a direct line to the till.

That reframes the requirements. Correctness first, visible failure second, and everything else — design, filters, features — a long way behind.

Four things that matter for a venue

Ordinal recurrence, correct. Venues run on “the first Friday”, “the last Saturday”, “every other Tuesday”. These are exactly the rules plugins expand wrongly, silently. Check yours against the expander above before it goes anywhere near print.

Cancelling one date, easily. Bands cancel. Weather happens. Cancelling one night must be a ten-second job that does not disturb the rest of the series or change anybody's links — because those links are in Facebook posts you cannot edit.

Times that survive October. A 20:00 door time is 20:00 on the wall, including the weekend the clocks change. A calendar that stores absolute instants will move it, and it moves it on precisely the weekend when your listings are busiest.

Visible failure. If your calendar syncs from somewhere and stops, the page shows nothing coming up — which looks like a quiet fortnight, not like a fault. You find out when a customer asks whether you have closed down.

The page itself

Lead with the next few nights rather than a month grid, unless you have something on most nights. Say “Tonight” and “Tomorrow” where they apply. Put the ticket link in the listing rather than one click further in. Design the empty state deliberately — “Autumn programme announced in September” beats “No upcoming events”, which reads as closed.

And give each show a real page with a real URL. “[band name] [your town]” is a search somebody makes, and it is free traffic that an embedded calendar widget cannot capture at all.

Let regulars subscribe

Publishing an .ics feed means somebody who comes every month can subscribe once and have your programme in their phone permanently, updating itself. It costs nothing per subscriber and it is worth more than a newsletter signup, because it requires no further decision from them ever again.

If the programme lives elsewhere

Many venues run the diary in Google Calendar or a booking system because that is where the promoter, the sound engineer and the bar manager can all see it. Point the website at that calendar's feed rather than maintaining a second copy — the copy nobody uses daily is always the one that ends up wrong.