Time Duration Calculator
Calculate the exact duration between two times in hours, minutes, and seconds. Perfect for UK work hours, timesheets, shift calculations, and payroll. Our calculator handles overnight shifts, break deductions, and converts to decimal hours automatically.
Calculate the duration between two times. Handles overnight shifts automatically.
Calculate net work hours with break deductions. Ideal for timesheets and payroll.
Add or subtract hours and minutes from a time.
Calculate the exact duration between two dates and times.
UK Working Time Regulations 1998
Under UK law, workers have specific rights regarding working hours:
- Maximum weekly hours: 48 hours per week (averaged over 17 weeks) unless opted out
- Daily rest: 11 consecutive hours rest between working days
- Rest breaks: 20-minute break if working more than 6 hours
- Weekly rest: At least 24 hours off per week (or 48 hours per fortnight)
- Night workers: Maximum 8 hours in any 24-hour period
Time to Decimal Hours Conversion
Convert minutes to decimal hours for payroll and timesheet calculations:
| Minutes | Decimal | Minutes | Decimal | Minutes | Decimal |
|---|---|---|---|---|---|
| 5 min | 0.08 | 25 min | 0.42 | 45 min | 0.75 |
| 10 min | 0.17 | 30 min | 0.50 | 50 min | 0.83 |
| 15 min | 0.25 | 35 min | 0.58 | 55 min | 0.92 |
| 20 min | 0.33 | 40 min | 0.67 | 60 min | 1.00 |
Common UK Shift Patterns
Standard shift durations used in UK workplaces:
| Shift Type | Typical Hours | Duration | With Breaks | Common Industries |
|---|---|---|---|---|
| Standard Day | 09:00 - 17:30 | 8.5 hours | 7.5 - 8 hours | Office, Admin, Finance |
| Early Shift | 06:00 - 14:00 | 8 hours | 7.5 hours | Manufacturing, Logistics |
| Late Shift | 14:00 - 22:00 | 8 hours | 7.5 hours | Retail, Hospitality |
| Night Shift | 22:00 - 06:00 | 8 hours | 7.5 hours | Security, Healthcare, Transport |
| Long Day (NHS) | 07:00 - 19:30 | 12.5 hours | 11.5 hours | NHS, Care Homes |
| Part-Time | 09:00 - 13:00 | 4 hours | 4 hours | Retail, Education |
| Continental (12hr) | 06:00 - 18:00 | 12 hours | 11 hours | Manufacturing, Processing |
British Summer Time (BST)
The UK observes British Summer Time from the last Sunday in March to the last Sunday in October:
Clocks Forward (Spring)
When: Last Sunday in March at 1:00am
Effect: 1:00am becomes 2:00am (GMT to BST)
Impact: Duration spanning 1am-2am is 1 hour shorter
2025: Sunday 30 March
Clocks Back (Autumn)
When: Last Sunday in October at 2:00am
Effect: 2:00am becomes 1:00am (BST to GMT)
Impact: Duration spanning 1am-2am is 1 hour longer
2025: Sunday 26 October
Tips for Accurate Time Calculations
- Use 24-hour format - Avoids AM/PM confusion, especially for overnight shifts
- Record exact times - Round to the nearest minute for accurate payroll calculations
- Document breaks separately - Keep records of unpaid break times for HMRC compliance
- Convert to decimal hours - Most payroll systems use decimal hours (7.5 instead of 7:30)
- Account for BST changes - Adjust calculations on clock change weekends (March/October)
- Check Working Time Regulations - Ensure compliance with maximum 48-hour average
- Keep timesheet records - Employers must keep records for 2 years minimum
- Include travel time if applicable - Some roles require travel time in working hours
Common Time Calculation Mistakes
- Forgetting AM/PM - 9:00 to 5:00 is 8 hours, but only if both are same AM/PM
- Not accounting for overnight shifts - 22:00 to 06:00 is 8 hours, not -16 hours
- Ignoring unpaid breaks - A 9-5:30 shift with 1-hour unpaid lunch is 7.5 hours, not 8.5
- Rounding incorrectly - 7 hours 45 minutes is 7.75 decimal hours, not 7.45
- Miscalculating overtime - Check if overtime is calculated daily or weekly
- Forgetting BST changes - Clock change days affect overnight shift durations
- Mixing paid/unpaid breaks - Only deduct unpaid breaks from work hours
- Using wrong week start - UK work weeks typically run Monday to Sunday
Frequently Asked Questions
Enter your start time and end time in 24-hour or 12-hour format. The calculator will show the duration in hours and minutes, total minutes, total seconds, and decimal hours. It automatically handles overnight shifts (e.g., 22:00 to 06:00) by detecting when the end time is earlier than the start time and adding 24 hours.
Under the UK Working Time Regulations 1998, workers cannot be forced to work more than 48 hours per week on average (calculated over 17 weeks). Workers are entitled to 11 consecutive hours rest per 24-hour period, a 20-minute break if working more than 6 hours, and at least one day off per week. Workers can opt out of the 48-hour limit by signing a written agreement.
To convert time to decimal hours, divide the minutes by 60 and add to the hours. For example: 7 hours 30 minutes = 7 + (30/60) = 7.5 decimal hours. Common conversions: 15 min = 0.25, 30 min = 0.50, 45 min = 0.75. Our calculator automatically shows decimal hours for easy timesheet and payroll calculations.
Yes! The calculator automatically detects overnight shifts. If your end time is earlier than your start time (e.g., 22:00 to 06:00), it correctly calculates across midnight. The result shows the actual duration (8 hours in this example) rather than a negative value.
Use the Work Hours mode and enter your start time, end time, and break duration in minutes. The calculator will deduct breaks from your total hours and show both gross and net working time. Under UK law, if you work more than 6 hours, you're entitled to at least a 20-minute unpaid rest break.
British Summer Time (BST) is when UK clocks go forward 1 hour on the last Sunday of March (GMT+1) and back on the last Sunday of October (GMT). On the spring clock change, a night shift crossing 1-2am will be 1 hour shorter (only 7 hours for a typical 10pm-6am shift). In autumn, it will be 1 hour longer (9 hours).
The standard UK full-time working week is typically 37.5 to 40 hours, usually worked over 5 days (Monday to Friday). This equates to 7.5-8 hours per day. Part-time work is anything less than full-time hours. The legal maximum average is 48 hours per week unless the worker has voluntarily opted out in writing.
Yes! Use the Date Duration mode to calculate the exact time between two dates and times. Enter both the date and time for start and end points. Results show the total duration in days, hours, minutes, and seconds, plus total hours for project tracking. This is useful for project timelines, booking durations, countdowns, or calculating periods.
Official UK Resources
GOV.UK - Working Hours
Official guidance on maximum weekly working hours, rest breaks, and opting out of the 48-hour limit.
Visit GOV.UKACAS - Working Time
Advice on working time regulations, rest breaks, and your rights as an employee or employer.
Visit ACASHMRC - Payroll Guidance
Information on payroll, timesheets, record keeping, and employer obligations for PAYE.
Visit HMRCNHS Employers - Working Time
Specific guidance on working time rules for NHS staff, including junior doctors and shift patterns.
Visit NHS EmployersCitizens Advice - Rest Breaks
Your rights to breaks at work, rest periods, and what to do if your employer isn't following the rules.
Visit Citizens AdviceRoyal Observatory Greenwich
Official UK time, British Summer Time dates, and the history of Greenwich Mean Time (GMT).
Visit Royal ObservatoryRelated Calculators
About This Time Duration Calculator
Our free UK Time Duration Calculator is designed specifically for UK users who need accurate time calculations for work, payroll, and everyday planning. Whether you're calculating shift hours, tracking project time, or working out timesheet entries, this tool provides instant results in multiple formats.
Key Features
- Multiple calculation modes - Time duration, work hours with breaks, add/subtract time, and date duration
- Overnight shift support - Automatically handles shifts that cross midnight
- Decimal hours - Converts to decimal format for payroll systems
- Break deductions - Calculate net work hours after unpaid breaks
- Earnings calculator - Optionally calculate pay based on hourly rate
- UK Working Time compliance - Reference information for UK employment law
- BST awareness - Information about British Summer Time clock changes
Who Uses This Calculator?
- Employees - Checking work hours and timesheet accuracy
- Employers - Calculating staff hours for payroll
- Freelancers - Tracking billable time for clients
- HR professionals - Ensuring Working Time Regulation compliance
- Shift workers - Planning rotas and calculating overnight hours
- Parents - Working out childcare hours and pickup times
Disclaimer: This calculator is provided for informational purposes. While we strive for accuracy, please verify important calculations with official sources. For employment law advice, consult ACAS or a qualified employment solicitor.
Pro Tips for Accurate Results
- Double-check your input values before calculating
- Use the correct unit format (metric or imperial)
- For complex calculations, break them into smaller steps
- Bookmark this page for quick future access
Understanding Your Results
Our Time Duration Calculator provides:
- Instant calculations - Results appear immediately
- Accurate formulas - Based on official UK standards
- Clear explanations - Understand how results are derived
- 2025/26 updated - Using current rates and regulations
Common Questions
Is this calculator free?
Yes, all our calculators are 100% free to use with no registration required.
Are the results accurate?
Our calculators use verified formulas and are regularly updated for accuracy.
Can I use this on mobile?
Yes, all calculators are fully responsive and work on any device.