How we work

We count whole days on the UK calendar, use the rules in law and GOV.UK's published dates, and show every count.

Our rules

Leap years follow the Calendar (New Style) Act 1750, the law that brought in the calendar Great Britain has used since 1752. British Summer Time follows the Summer Time Act 1972 and the Summer Time Order 2002. Bank holidays, including Good Friday, Easter Monday and Christmas, come from GOV.UK. Each rule is recorded with its source and the date we checked it, and the site will not build if one is missing. You can see them all.

How we count

Dates are counted in whole days. A count from one date to another runs from the start of the first day to the start of the last, so 1 to 2 January is one day, unless you choose to count both. Calculators that start from today use today's date in the UK, so they change at midnight UK time wherever you are.

Our calculators give information, not advice. For a legal or contractual deadline, check the date with whoever set it.

How we test the counts

Every calculation is tested. The clock change dates are tested against the dates GOV.UK publishes, Easter against GOV.UK's bank holidays, leap years against the rule in the Act (2000 was a leap year, 1900 and 2100 are not), and week numbers against the ISO 8601 standard, including years with a week 53.

Corrections

We have not had to correct anything yet. If you spot a mistake, email max@youellsystems.co.uk.