Guide
Deadlines that land on a weekend or a public holiday
You add thirty days to the date on a letter and the answer is a Sunday. Is the deadline that Sunday, the Friday before, or the Monday after? All three appear in real rules, and the answer is never obvious from the arithmetic. It comes from the rule that governs the deadline.
The three conventions
- Roll forward. The deadline moves to the next working day. This is the most common convention in civil procedure and in commercial contracts, and it favours the party who has to act.
- Roll back. The deadline moves to the previous working day. Common where something has to be received and processed by a fixed date, such as payments before a cut-off.
- No adjustment. The date stands, weekend or not. Usual where the action does not need anyone at a desk, such as an online submission or an automatic renewal.
Public holidays follow the same logic, locally
Where a rule rolls around weekends, it usually rolls around public holidays too, and those are local. A deadline that is comfortable in one country can fall inside a four-day holiday weekend in another. In cross-border matters the governing law decides whose holidays count, which is one more reason for a contract to name it explicitly.
Time of day is part of the deadline
A date without a time is an incomplete deadline. Filing systems often close at a specific hour, and that hour is in a specific time zone. If you are submitting from a different country, convert the cut-off into your own local time before you plan around it, and leave margin: a deadline of 17:00 in one capital is the middle of the night in another.
Practical habits
- Compute the raw date first, then apply the rolling rule, then write down the final date and time with its zone.
- Confirm the adjusted date with the other side in writing. Two parties applying different conventions in good faith is a common and avoidable dispute.
- Aim to act a working day early. Every convention above is satisfied by being early, and none of them is satisfied by being right about the rule and late.
For the arithmetic itself, the add days to a date tool shows the resulting date and the weekday it falls on, which is the fact you need before you can decide which way the deadline rolls.