Time Duration Calculator
Calculate hours and minutes between two times. Includes decimal hours for timesheets.
By Konstantin Iakovlev · Founder, Calks.uk
Last updated: · Verified against HMRC and GOV.UK 2026/27 rates
Start Time
End Time
Duration
8h 30m
510 minutes · 8.50 decimal hours
Disclaimer
This calculator is provided for informational purposes only and should not be considered as financial or tax advice. All calculations are performed locally in your browser — no personal data is collected or sent to our servers. Rates and thresholds are sourced from HMRC and GOV.UK and are updated for the current tax year. Always verify results with HMRC or consult a qualified professional before making financial decisions.
How It Works
This calculator finds the duration between two times in hours, minutes and seconds. It handles overnight spans that cross midnight correctly. You can also add or subtract a duration from a start time to find the end time.
The tool is useful for calculating shift lengths, journey times, cooking durations and billable hours. Enter times in either 12-hour (am/pm) or 24-hour format. Results are shown in both total minutes and the hours-and-minutes breakdown.
Calculating time differences. Hours between two times: convert both to total minutes/seconds, subtract, convert back. Sample 9:15 AM to 5:45 PM: (17×60 + 45) − (9×60 + 15) = 1065 − 555 = 510 minutes = 8h 30min. Days between dates: simple calendar subtraction. Working days: exclude weekends + 8 UK bank holidays. Hours per week: total work hours ÷ 52 weeks for annual figure.
UK working time conventions. Standard full-time: 35-40 hours/week. Working Time Regulations max: 48 hours/week (averaged over 17 weeks) unless opted out. Annual hours: 1,700-1,800 typical (minus 28-day holiday + 8 bank holidays + sickness). Statutory holiday: 5.6 weeks × normal week (28 days for 5-day worker). Part-time pro-rata: 22.5-hour week → 16.8 days holiday.
Common UK statutory time periods. Cooling-off period (online consumer purchases): 14 calendar days from delivery. Employment Tribunal claim deadline: 3 months less 1 day from incident. Personal injury claim: 3 years from injury/knowledge. Contract claim limitation: 6 years (12 years for deeds). HMRC tax assessment: 4 years standard, 6 careless, 20 deliberate. Probate executor's year: 12 months from grant. CGT 60-day window for residential property reporting/payment.
How long do common UK processes take? Buying a house: 12-16 weeks offer-to-completion. Selling: 22 weeks total. HMRC tax refund: 2-12 weeks. Probate: 8-16 weeks (currently delayed 6+ months in some). Passport renewal: 3-10 weeks. Driving test wait: 14-20 weeks 2025. NHS GP same-day appointment: <50% achievable. Hospital referral 18-week target: 65% met (NHS England 2024). Divorce minimum: 26 weeks (no-fault since April 2022).
Time conversions and leap years. 1 year average = 365.2425 days (Gregorian). Leap year: every 4 years EXCEPT centuries not divisible by 400. 2000 was leap, 1900 wasn't, 2100 won't be, 2400 will be. Average month: 30.44 days. Age in seconds: 30 years ≈ 946 million; 100 years ≈ 3.15 billion. Quick math: 1 year ≈ 31.5 million seconds; 1 day = 86,400; 1 week = 604,800. Working day 8 hours = 28,800 seconds.
Example: Duration from 09:15 to 17:45
- Duration: 8 hours 30 minutes
- Total minutes: 510
- In decimal hours: 8.50
Frequently Asked Questions
- Working time conversions — UK standard.
- Standard UK full-time week: 35-40 hours. Working Time Regulations: max 48 hours/week (averaged over 17 weeks) unless opted out in writing. Annual: 2,080 hours/year theoretical (40×52); typical UK full-time = 1,700-1,800 hours (minus 28-day holiday, 8 bank holidays, sickness). Statutory min holiday: 5.6 weeks × normal week (28 days for 5-day worker including bank holidays). Part-time pro-rata: 22.5-hr week → 16.8 days. Overtime in UK: no statutory premium — paid at employer's contract rate.
- Common time-period UK legal deadlines.
- Cooling off: 14 calendar days (consumer rights, distance contracts). Employment claim: 3 months less 1 day from last incident (Tribunal). Personal injury: 3 years from injury or knowledge. Contract claim: 6 years (12 years for deeds). Tax assessment: 4 years standard, 6 years if careless, 20 years if deliberate. Estate executor: 12 months 'executor's year' to settle. Mortgage approval validity: typically 90-180 days then re-assess. UK passport renewal: process 3-10 weeks (priority 1 week).
- How long does X take in the UK?
- Buying a house: average 12-16 weeks offer-to-completion. Selling: 22 weeks total (listing-to-completion). HMRC tax refund: 2-12 weeks after filing. Probate: 8-16 weeks (currently delayed 6+ months in some cases). Passport renewal: 3-10 weeks. Driving test wait: 14-20 weeks 2025. Marriage notice period: 28 days minimum (UK register office, since 2015). NHS GP appointment same day: <50% achievable. Hospital referral 18-week target: 65% met (NHS England 2024).
- Time conversions — leap years and ages.
- 1 year = 365.2425 days average (Gregorian). Leap year every 4 years EXCEPT centuries not divisible by 400. 2000 was leap, 1900 wasn't, 2100 won't be, 2400 will be. Days in centuries: average 36,524.25 days. 1 month: varies 28-31 days, average 30.44. Age in seconds: 30 years ≈ 946 million seconds; 100 years ≈ 3.15 billion. Quick mental math: 1 year ≈ 31.5 million seconds; 1 day = 86,400 seconds; 1 week = 604,800 seconds.