How event dates are set

“When is it?” has a different answer depending on what kind of event you are asking about. Some dates are decided by a committee, some by arithmetic, some by the weather. The difference decides how early you can book without gambling.

Dates that never move

The simplest category. San Fermín opens at noon on 6 July and ends at midnight on 14 July — every year, fixed to the saint’s day, unchanged for centuries. Book years ahead if you like; the date will be there.

Dates set by a rule

Plenty of events have no announcement to wait for because a rule decides them.

• The Boston Marathon is Patriots’ Day, the third Monday in April — 19 April 2027.
• The New York Marathon is the first Sunday in November — 7 November 2027.
• Super Bowl LXI is the second Sunday in February — 14 February 2027, which is also Valentine’s Day.
• Oktoberfest runs sixteen days from the Saturday after 15 September, ending on the first Sunday in October, extended to 3 October when German Unity Day falls just after. In 2027 that is 18 September to 3 October.
• The Nuremberg Christkindlesmarkt opens on the Friday before the first Advent and closes on 24 December.

You can act on these before anyone confirms them. We still mark a page expected rather than confirmed until the organizer says so — the rule is reliable, but it is not an announcement.

Dates calculated from Easter

Carnival is the big family here, and it moves by weeks from year to year. Easter 2027 falls on 28 March, which sets Ash Wednesday at 10 February and therefore Shrove Tuesday — Fat Tuesday, Martedì Grasso — at 9 February 2027.

That single calculation fixes three events on this site at once: Mardi Gras in New Orleans, Rio Carnival and the Venice Carnival, which all end on the same day. If you are planning two of them in one year, they are always in the same fortnight and never overlap conveniently.

Dates a governing body publishes

Motorsport and tennis run on calendars approved by a federation, usually a year ahead. The thing to know is that these are published as provisional: the FIM issues the MotoGP calendar and confirms it after each circuit is homologated.

In practice, slots rarely move — the Dutch TT and the Italian GP have held theirs since the September 2026 release — but a first-year venue is where the risk sits. The Australian GP in Adelaide is new for 2027, on a street circuit that did not exist before, and its page says so.

Dates nobody controls

Cherry blossom season has no organizer at all. The trees open when the winter and the spring decide, around 25 March in Tokyo in a normal year, with Kyoto roughly a week behind. Forecasters publish projections from January and refine them weekly, and the real answer is known about ten days out — long after the hotels have gone.

The only strategy that works is a refundable booking across a ten-day window rather than a bet on one weekend.

What our labels mean

Every date on this site carries one of two statuses, and the badge on the event page links to the proof.

Confirmed means the organizer, or the body that publishes the calendar, has announced it, and we link to that announcement. We never cite an aggregator for a date.

Expected means no announcement yet, and the date follows the pattern above. As of now that applies to the New York Marathon, Tomorrowland in Boom, Super Bowl LXI, Edinburgh’s Hogmanay and the cherry blossom — and each page says which rule it is following.

If a date changes, the page changes with it, and the “updated” line at the bottom tells you when we last looked.