When are the Boards of Appeal on holiday, and when is the best time for oral proceedings?

Every year the European Patent Office publishes the days on which its filing offices are closed. For 2026 the list runs to sixteen days (OJ EPO 2025, A40). That the Boards of Appeal also go quiet when Bavaria goes on holiday will surprise nobody who has tried to obtain a summons for the second week of August. What the decision dates show is less expected. The holiday is not felt as a missing hearing date. It is felt afterwards, as a longer wait for the written decision, and the wait is longest for hearings held in the weeks before the holiday, not during it.

What was measured

The decision date and the online publication date of every decision of the Technical Boards of Appeal (T decisions) from 2015 to 2025 were taken from the EPO case law database, 16,575 decisions after 2020 was set aside. The decision date is the date of the oral proceedings or, in written proceedings, the date on which the decision is handed over to the postal service. It is a proxy for hearing activity. The number of days between the two dates is the wait for the written reasons, which is the interval that matters to the parties.

These dates were laid against the Bavarian school holiday calendar published by the Bavarian Ministry of Education. Bavarian public holidays were removed from the working-day base. Bavaria is the relevant calendar because the Boards have their seat in Haar, in the district of Munich. The explorer below is computed live from the same corpus, so the figures move as new decisions are added. Every panel follows the board selected at the top.

Finding one: the wait for the reasons has a season

Across all boards the median wait from the decision date to online publication is 43 days. It is not constant. A decision dated in the first week of July waits a median 60 days for its reasons; in the last week of August, 29 days. Decisions dated in the last week before Christmas wait about 65 days. The pattern is the same every year.

The explanation is mundane and worth stating plainly. A hearing in early July produces a decision that has to be written in the weeks when the rapporteur is on holiday, so it is published in September. A hearing in late August, held by a board that sat through the holiday, is written straight away in an empty building. The holiday's cost therefore falls on the parties whose hearings came just before it, and the reader planning a file should count backwards from the holiday, not forwards.

The wait also differs by kind of case and by board. Ex parte decisions are online after a median 28 days, inter partes decisions after 50. Between boards the spread is wider still: the fastest board publishes within about three and a half weeks, the slowest takes more than three months, and for some boards a July hearing adds a further month on top. The table in the explorer lists both figures for every board.

Why the wait matters more than the hearing date

The wait is the interval in which the parties act on a decision they cannot yet read: whether to file a petition for review, whether to keep paying, whether to adapt the parallel national or UPC proceedings. In the extreme case the calendar wins outright. In R 4/25 the written decision arrived on 8 January 2025, six days after the six-month window under Rule 51(2) EPC for an unpaid renewal fee had closed, and the petition for review could not restore it. Such cases are rare. The ordinary consequence of a long wait is simply that a July hearing produces a decision the parties read in September.

The date tool at the top of the explorer returns, for a hearing date and a board, the typical wait for the reasons and the date they are likely to be online. It is a rule of thumb from historical medians, not a prediction for a specific file; a quarter of decisions take longer than the third-quartile figure shown in the tooltip.

Finding two: the Boards keep the Bavarian school holidays, but not the Whitsun ones

Decisions per working day inside each Bavarian school holiday, as a share of the pace outside all school holidays:

Easter is the clearest signal. The EPO closes for Good Friday and Easter Monday; the Boards run at 28% of their pace for the full two Bavarian weeks around them, and the dip begins in the week before. The two Whitsun weeks, by contrast, barely register at 64%, less of a slowdown than the single Fasching week in February. Whoever wants a summons in a Bavarian school holiday should ask for Whitsun.

Because Easter and Whitsun move by up to five weeks from year to year, a plain calendar average smears them. The "pace by holiday" panel in the explorer shifts each year so that its own holiday dates coincide before averaging, which is why every curve dives into the shaded window and climbs out at its edge. Summer has one further detail: the quiet period ends around 2 September in most years, a week before Bavarian schools reopen. The Boards take five weeks, not six.

Finding three: the boards differ more than the fields

Not every Technical Board keeps the holidays to the same degree, and the difference is not one of subject matter. Of the 28 boards with at least 150 decisions, the most holiday-observant dates 8% of its decisions inside Bavarian school holidays and runs at about a quarter of its usual pace when schools are closed. The least observant dates 19% inside school holidays and runs at almost two thirds of its pace. For comparison, 26% of working days fall inside school holidays. Grouped into mechanics, chemistry, physics and electricity, the four fields sit within a few points of each other, so the rhythm is set by the members of each board rather than by the technology.

Christmas is the one window that applies to everyone. No board issues a meaningful number of decisions between 24 December and Epiphany, and the EPO itself is closed from 24 December to the end of the year.

Two smaller regularities are visible in the year calendar. Tuesday is the Boards' hearing day, with roughly twice as many decisions dated on a Tuesday as on a Monday. And the Friday after Ascension Day carries about a fifth of the normal output. Across a year, about 43 working days fall below half of the normal pace, against the sixteen closing days that are published.

What to do with it

None of this is a criticism of the Boards. An institution seated in Bavaria whose members have families in Bavaria will keep Bavarian rhythms, and the Rules of Procedure of the Boards of Appeal say nothing about school holidays because they do not need to. The point is practical. The closing-day notice under Rule 134(1) EPC governs time limits, and only time limits.

1. Count the wait from the hearing, not the hearing from the holiday. A hearing in the last three weeks before the Sommerferien or the Weihnachtsferien is the one most likely to leave a party without written reasons for two months. Anything that has to be decided in that interval is decided without the reasons.
2. Before requesting a postponement into a school holiday, look up the board. The table shows which boards sit through the Osterferien and Sommerferien and which do not.
3. A hearing held during the holidays is not the worst outcome. Those decisions are, on the data, the fastest to be written.

Sources: decision and publication dates of T decisions from the EPO Boards of Appeal decisions database, 2015 to 2025, 2020 excluded. Bavarian school and public holidays from the Bavarian Ministry of Education. EPO closing days: OJ EPO 2025, A40. Method: decisions per working day inside each holiday window divided by decisions per working day outside all school holidays; wait is the median of days from decision date to online publication, by ISO week of the decision date; public holidays excluded from the working-day base; aligned curves use a one-week rolling mean.