How many days between two dates

The third number is the one you came for

Calendar days between two dates is a subtraction any calculator does. Working days between them is a subtraction with weekends taken out, which most date calculators also do. Working days with Irish public holidays taken out is the count that actually matters for a notice period, a deadline or a lead time — and a generic date calculator cannot give it to you, because it does not know which days those are.

This one does, and it gets them from the same place the calendar pages get them: the statutory rules in this site’s payload, evaluated for whatever years your range spans. The three pages cannot disagree about a date because there is only one source behind them.

Which holidays it can remove

Only those falling Monday to Friday, because a holiday at a weekend was never in the working-day count to begin with. In 2026 that is 9 of the ten:

The counting convention, stated

The count runs from the first date up to but not including the second. Two consecutive days are one day apart, not two. That is the convention a notice period uses and the one that makes “thirty days from today” land where you expect.

It is also a choice, and stating it matters more than which one it is: half the date calculators on the internet count inclusively and do not say so, which is how two people with the same two dates get answers a day apart and both believe they are right.

What this is not

It is not a legal deadline calculator. A statutory time limit may be counted in clear days, may exclude the day of an event, may run to the next working day if it would otherwise end on a weekend, and may be defined in months rather than days — and which of those applies is a question about the particular provision, not about the calendar.

What this gives you is an accurate count of days. Applying the right counting rule to your situation is the part it cannot do for you, and a calculator that pretended otherwise would be more dangerous than useful.

Range limit

Twenty years. Beyond that the calculator declines rather than answering, because the public-holiday rules it is applying are the ones in force today — projecting them across decades would produce a confident calendar for years whose law has not been written yet. The February holiday, for instance, did not exist before 2023, and the calculator correctly produces no row for it in earlier years rather than a row with a blank.