Date Calculator — Days Between Dates

This calculator finds the exact number of days, weeks, months and years between any two dates. You can choose to include or exclude weekends and UK bank holidays, making it useful for calculating working days for employment notice periods, project timelines or legal deadlines.

The UK has eight permanent bank holidays in England and Wales (Scotland has nine, Northern Ireland has ten). When calculating business days, the tool accounts for these automatically based on the nation you select. It also handles leap years correctly.

You can also add or subtract a set number of days, weeks or months from a given date. This is handy for calculating due dates, contract expiry or the end of a notice period.

Adding and subtracting time periods. Days: simple calendar arithmetic — 15 March + 90 days = 13 June. Months can be ambiguous: 31 January + 1 month = 28 February (or 29 in leap year). UK contract law typically reads 'one month from' as 'the same date next month, or last day if absent'. Years: 29 February 2024 + 1 year = 28 February 2025 (no Feb 29 in 2025). Always specify whether you mean calendar months or 30-day blocks in legal documents.

Working days vs calendar days — UK rules. Working days exclude weekends and English/Welsh bank holidays (typically 8 per year, more in Scotland and Northern Ireland). HMRC and Companies House count business days for many filing deadlines. Civil Procedure Rules (CPR Part 2): 'days' usually means clear days excluding the day of the act and the day of expiry. Example: 30 calendar days from 1 Dec 2026 = 31 Dec 2026; 30 working days = approximately 12 Feb 2027 (depending on Christmas/New Year holiday distribution).

Common UK statutory time periods you should know. Consumer cooling-off (distance contracts): 14 calendar days from delivery. Employment Tribunal claim: 3 months less 1 day from incident. Statute of limitations on contract: 6 years (12 years for deeds). Personal injury: 3 years. Tax assessment by HMRC: 4 years standard, 6 years if careless, 20 years if deliberate. Capital Gains Tax 60-day window for residential property disposal reporting/payment. Probate executor's year: 12 months from grant.

UK term and academic dates. Academic year runs September–July for schools, October–June for universities. University semesters: typically 12 teaching weeks per semester. ISA tax year: 6 April – 5 April (same as tax year). Companies House accounting reference: anniversary of incorporation month. Local council year: 1 April – 31 March (used for Council Tax, business rates, election cycles). Government fiscal year: 1 April – 31 March (different from individual tax year by 5 days, a historical quirk).

Date counting between two events. Subtraction is straightforward: 5 Oct 2026 – 12 March 2024 = 2 years 6 months 23 days. Total days = 938. Anniversary calculations: same date plus N years. Leap year complication: someone born on 29 Feb 2024 has next 'real' birthday 29 Feb 2028 — most legal documents accept 28 Feb or 1 March in interim years. Use ISO 8601 format (YYYY-MM-DD: 2026-03-15) for unambiguous dates — UK format DD/MM/YYYY (15/03/2026) and US MM/DD/YYYY (03/15/2026) cause confusion across borders.