Time & Date Tools

Hour Difference Calculator

Calculate hours and minutes between two times, total work hours with breaks, weekly time card totals, overnight shift duration, pay earned from hours worked, and time-to-decimal conversion — with full step-by-step working.

5 Calculation Modes
Overnight Shifts
Weekly Time Card
Pay from Hours
100% Free
Updated April 2026
Before You Calculate

Why Time Calculations Are Harder Than They Look — and How to Get Them Right

April 2026  ·  4 min read  ·  Keeroot Solutions

Time arithmetic looks simple until you actually do it. The problem is that time is base-60 (hours) and base-24 (days), not base-10 like money or distance. You cannot add hours and minutes the way you add dollars and cents. 8 hours 45 minutes + 3 hours 30 minutes is not 11 hours 75 minutes — it is 12 hours 15 minutes. The carry-over from minutes to hours happens at 60, not 100. This is where most manual timesheet calculations go wrong, and where small errors compound into meaningful pay discrepancies over a week or month.

The decimal representation adds another layer of confusion. Time on a clock is expressed in hours and minutes (HH:MM). Time in calculations, payroll systems, and spreadsheets is expressed in decimal hours (where 30 minutes = 0.5 hours, 45 minutes = 0.75 hours, 20 minutes = 0.333 hours). The formula: Decimal Hours = Hours + (Minutes ÷ 60). The decimals for thirds are recurring (20 min = 0.3333…, 40 min = 0.6667…), which creates rounding errors in spreadsheets that use ROUND() to 2 decimal places.

The Five Modes — Which Do You Need?

Basic Time Difference — How many hours and minutes between two times. Handles overnight correctly (9 PM to 6 AM = 9 hours, not −15 hours). Use for: shift duration, meeting length, task tracking.

Net Hours with Break — Start and end time minus an unpaid break. The correct formula: Net = (End − Start) − Break. Use for: timesheet calculation where a 30 or 60 minute unpaid lunch affects payable hours.

Weekly Time Card — Sum up to 7 days of shifts with individual break deductions. Calculates total hours, daily average, and overtime. Use for: weekly payroll preparation, cumulative work hour tracking.

Pay Calculator — Converts hours to earnings at a given hourly rate. Converts HH:MM to decimal before multiplying — avoiding the common error of treating 7:20 as 7.20. Use for: freelancer invoicing, pay verification.

Time Converter — Converts between HH:MM format and decimal hours in both directions. Use when reconciling a spreadsheet that uses decimals against a time clock that uses HH:MM. Also see our Date Difference Calculator and Digital Detox Calculator for related time tools.

⏰ Time Insight
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Hour Difference Calculator

Enter your times — get hours, minutes, decimals, pay earned, and a full visual breakdown

days
Supports overnight shifts automatically — if end time is before start time, one day is added. Use Extra Days for shifts spanning 2+ days. Input uses 24-hour format (e.g. 17:00 = 5:00 PM).
9 AM – 5 PM (8 hrs)
8:30–5:30 (9 hrs)
Night shift 10PM–6AM
7:45–4:15 PM
Near full day
⏱️ TIME DIFFERENCE
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Time Summary
Step-by-Step Calculation
Context & Notes
All Time Representations
Full Details
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    Complete Time Calculation Formula Reference — Every Formula with Examples

    All formulas for hours, minutes, decimals, overtime, and pay — with worked examples

    CalculationFormulaExample
    Time DifferenceEnd Minutes − Start Minutes17:30 − 09:00 = 510 min = 8h 30m
    Overnight Shift(End + 1440) − Start22:00→06:00: (360+1440)−1320 = 480 min = 8h
    Net Work (with break)Total Elapsed − Break Minutes9h total − 30 min lunch = 8h 30m net
    Decimal HoursHours + (Minutes ÷ 60)7h 45m = 7 + 45÷60 = 7.75 hrs
    Minutes to H:M⌊min÷60⌋h + (min mod 60)m510 min = ⌊510÷60⌋ = 8h, 510 mod 60 = 30m = 8h 30m
    Regular PayRegular Hours × Hourly Rate40 hrs × $22.50 = $900.00
    Overtime PayOT Hours × Rate × Multiplier8 hrs × $25 × 1.5 = $300.00
    Weekly OT (FLSA)Total Hours − 40 = OT Hours48 hrs − 40 = 8 OT hrs
    Annual SalaryHourly Rate × 40 × 52$25/hr × 2,080 hrs = $52,000/yr
    Hourly from SalaryAnnual Salary ÷ 2,080$62,400 ÷ 2,080 = $30.00/hr
    Daily PayHourly Rate × Daily Hours$18 × 8.5 hrs = $153.00/day
    Hours to DaysTotal Hours ÷ 2436 hrs ÷ 24 = 1.5 days

    Time Calculation Essentials — Everything You Need to Know About Work Hours

    Time formats, decimal conversion, overtime rules, shift types, and payroll compliance explained

    Core Concepts

    Calculating hours between two times is fundamentally simple — but becomes complex in real-world scenarios involving overnight shifts, lunch breaks, multiple days, and overtime thresholds. The foundation is always the same: convert both times to a common unit (minutes since midnight), subtract, then convert back to hours and minutes.

    The decimal hour format is essential for payroll. Because time-keeping software, spreadsheets, and pay stubs use decimal numbers (not hours:minutes), converting correctly is critical. The rule: divide minutes by 60. So 7 hours 30 minutes = 7.5 hours (not 7.30 — a common, costly mistake).

    ⚠️ Most common time calculation mistake: treating 7h 30m as 7.30 decimal hours instead of 7.50. At $25/hour over a year (52 weeks × 5 days), this error adds up to $2,600 in underpaid wages. Always divide minutes by 60, not just append them as decimals.
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    Overnight Shifts Explained
    When end time is earlier than start time, the shift crosses midnight. Add 24 hours (1440 minutes) to the end time before subtracting. Example: 10:00 PM (22:00) to 6:00 AM = (6:00 + 24:00) − 22:00 = 30:00 − 22:00 = 8 hours. Most time calculation errors with overnight shifts stem from forgetting this step.
    ☕
    Paid vs Unpaid Breaks
    Under the FLSA, short rest breaks of 5–20 minutes must be paid. Meal breaks of 30+ minutes where the employee is fully relieved of duties are generally unpaid. Many time cards subtract only unpaid meal breaks from total hours. Check your employer's policy — some pay all breaks, some pay short breaks only, and some (incorrectly) deduct all breaks. State laws may add additional requirements.
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    Overtime Thresholds by Region
    US Federal (FLSA): OT after 40 hrs/week at 1.5×. California: OT after 8 hrs/day AND after 40 hrs/week; double time after 12 hrs/day. Canada: varies by province (typically 44 hrs/week). UK: no legal OT rate — contractual only. EU: max 48 hrs/week (Working Time Directive). Australia: varies by award/agreement, typically 38 hrs/week. Always check local law.
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    Annual Hours by Work Pattern
    Full-time (5×8): 40 hrs/wk × 52 = 2,080 hrs/yr. Part-time (5×4): 20 hrs/wk × 52 = 1,040 hrs/yr. 4-day week (4×9): 36 hrs/wk × 52 = 1,872 hrs/yr. Compressed (4×10): 40 hrs/wk × 52 = 2,080 hrs/yr. Accounting for US holidays (~10 days) and 2 weeks vacation reduces billable hours to ~1,880/yr. Freelancers often calculate rates on 1,800 billable hours.

    Minutes to Decimal Hours Conversion Table — All 60 Minutes

    Quick reference for converting any minutes value to its decimal hour equivalent

    MinutesDecimal HrsFraction
    MinutesDecimal HrsFraction
    💡 Quick formula: Decimal Hours = Hours + (Minutes ÷ 60). Remember: 30 min = 0.50, 15 min = 0.25, 45 min = 0.75. These are the most common — memorise them for quick mental calculations.

    8 Time & Work Hours Facts, Tips & Strategies Every Worker Should Know

    Practical insights on time tracking, overtime, scheduling, and maximising accuracy

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    The Decimal Mistake That Costs Billions

    Studies estimate that time-rounding and decimal conversion errors cost US workers billions annually in lost wages. The most common: recording 7:30 hours as 7.30 instead of 7.50. Over a year, this 0.20-hour daily error at $20/hour = $1,040 in underpaid wages. Always use the Hours + (Minutes÷60) formula. For payroll software, verify by multiplying decimal hours × 60 to confirm the minutes match.

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    Time Rounding Rules in Payroll

    The FLSA permits employers to round employee time to the nearest 5, 6, or 15 minutes — but only if rounding is neutral over time (as many rounds up as down). The most common is "rounding to the nearest quarter hour": 1–7 minutes rounds down, 8–14 rounds up to the next 15 minutes. If an employer consistently rounds down, this is a wage violation. Track your own exact hours and compare to your pay stub to catch systematic under-rounding.

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    Night Shift Differential Pay

    Many employers pay a shift differential — extra pay (typically 10–20%) for working evenings or nights. Federal workers under the FLSA are not automatically entitled to shift differentials, but many collective bargaining agreements and employer policies require them. Common differentials: Evening (3–11 PM): +10–15%, Night (11 PM–7 AM): +15–25%, Weekend nights: +20–30%. Calculate your total pay by multiplying your differential hours by your adjusted rate.

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    Why Accurate Time Cards Matter

    Time card accuracy is a two-way street. Under-recording hours is a form of wage theft against yourself. Over-recording is a policy violation and can result in termination. The FLSA requires employers to keep records of hours worked for at least 2 years. Best practices: record start and end times (not just hours worked), note break times separately, and review your pay stub every period. Discrepancies should be reported immediately — the statute of limitations is 2–3 years.

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    The 4-Day Workweek and Hours

    The 4-day workweek can be structured two ways: Compressed (4×10) — same 40 hours over 4 days (still triggers OT after 40hrs/week under FLSA). Reduced (4×8 or 4×9) — fewer total hours. Microsoft Japan's trial of a 4-day, 32-hour week showed 40% productivity gains. Iceland's trials of 35–36 hour weeks showed maintained or improved performance with better well-being. Hour calculation remains the same — just with a different weekly total.

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    Converting Between Time and Salary

    The standard full-time equivalent is 2,080 hours/year (40 hrs × 52 weeks). To convert: Hourly → Annual: ×2,080. Annual → Hourly: ÷2,080. Quick estimates: $10/hr = $20,800/yr. $20/hr = $41,600/yr. $50,000/yr ÷ 2,080 = $24.04/hr. $100,000/yr ÷ 2,080 = $48.08/hr. Note: these are gross figures before any taxes or benefits deductions.

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    Global Work Hours by Country

    Average annual hours worked varies dramatically worldwide. Highest: Mexico ~2,128 hrs, South Korea ~1,901 hrs, US ~1,811 hrs. Lowest: Germany ~1,349 hrs, Netherlands ~1,427 hrs, Norway ~1,427 hrs. The difference between the US and Germany is ~462 hours/year — nearly 12 full 40-hour work weeks. Productivity per hour, however, often trends inversely — countries with fewer hours frequently show higher output per hour worked.

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    Tracking Billable Hours as a Freelancer

    Freelancers typically use one of three billing models: Hourly — track exact time with apps (Toggl, Harvest, Clockify). Project-based — estimate hours upfront, track to ensure profitability. Retainer — fixed monthly fee for a set number of hours. Best practice: log time in 15-minute increments, track all client communication time (not just "work" time), and review weekly utilisation (billable hours ÷ total hours worked × 100). 75–85% utilisation is a healthy target for a solo freelancer.

    How to Use This Hour Difference Calculator — All 5 Modes Explained

    Step-by-step guide to every calculation mode with tips on getting accurate results

    • 1
      Basic Mode — Hours Between Any Two Times

      Enter a start time and end time using the time pickers (24-hour format). The calculator handles overnight shifts automatically — if end time is earlier than start time, it assumes the shift crosses midnight and adds 24 hours. For shifts spanning more than one full calendar day, enter the number of extra days. The result shows hours and minutes, decimal hours, total minutes, and total seconds. The visual clock display shows start → duration → end at a glance.

    • 2
      With Break Mode — Net Work Hours After Deducting Breaks

      Enter shift start, shift end, lunch break duration, and any additional breaks (all in minutes). The calculator computes total elapsed time, total break time, and net work time (elapsed − breaks). Optionally enter your hourly rate to see how much you earned during the net work period. The timeline bar chart visually shows work time vs break time as proportions of the total shift.

    • 3
      Time Card Mode — Full Weekly Hours & Overtime

      Enter start time, end time, and break minutes for each day of the week. Daily hours update live as you type. The weekly total automatically shows regular hours, overtime hours (above the threshold you set), total pay (if rate entered), and overtime premium pay. Click the example presets to instantly fill a standard week, 4-day week, or an overtime week to see how the calculations work before entering your own data.

    • 4
      Pay Mode — Earnings from Hours Worked

      Enter hours worked, any extra minutes, your hourly rate, overtime hours (out of the total), and the overtime multiplier. The calculator computes regular pay, overtime premium pay, total gross pay, and derived annual salary equivalent. Particularly useful for verifying a paycheck — enter exactly what your time card shows and compare to what you were paid. The step-by-step working shows each calculation clearly.

    • 5
      Convert Mode — Time Format Conversion (Live)

      All four fields (hours, minutes, decimal hours, total minutes) update instantly as you type in any field. This is the fastest way to convert between formats — type a decimal like 8.75 and instantly see it's 8 hours 45 minutes. Or type 510 minutes and see 8 hours 30 minutes and 8.5 decimal hours simultaneously. The result section also shows days, seconds, and milliseconds for completeness.

    Hour Difference Calculator — Frequently Asked Questions

    Expert answers to the most commonly searched time calculation questions

    How do I calculate hours between two times?
    Convert both times to minutes since midnight (hours × 60 + minutes), then subtract: Total Minutes = End Minutes − Start Minutes. If the result is negative (overnight shift), add 1440 (24 hours × 60). Divide by 60 for decimal hours, or use ÷60 for the hours part and mod 60 for the remaining minutes. Example: 9:15 AM to 5:45 PM = (17×60+45) − (9×60+15) = 1065 − 555 = 510 minutes = 8 hours 30 minutes = 8.50 decimal hours.
    How do I convert minutes to decimal hours?
    Divide the minutes by 60 and add to the hours: Decimal = Hours + (Minutes ÷ 60). Examples: 7h 30m = 7.500, 8h 15m = 8.250, 6h 45m = 6.750, 4h 20m = 4.333, 9h 50m = 9.833. Common fractions: 15 min = 0.25, 20 min = 0.333, 30 min = 0.50, 40 min = 0.667, 45 min = 0.75. To verify, multiply the decimal part by 60 to get back the minutes. Critical warning: 7h 30m ≠ 7.30 hours. This is the most common payroll mistake — always divide minutes by 60.
    How do I calculate an overnight shift?
    For any shift where the end time is before the start time, add 24 hours to the end time: Duration = (End Time + 24:00) − Start Time. Example: Night shift 10:00 PM to 6:00 AM = (06:00 + 24:00) − 22:00 = 30:00 − 22:00 = 8 hours. In minutes: (360 + 1440) − 1320 = 1800 − 1320 = 480 minutes = 8 hours. This calculator handles overnight shifts automatically — simply enter the times as-is and it detects when the shift crosses midnight.
    How do I calculate hours worked per week with overtime?
    Add up daily hours for all days worked. If total exceeds 40 hours (US FLSA), the excess is overtime. Regular hours = min(total, 40). OT hours = max(0, total − 40). Regular Pay = Regular Hours × Rate. OT Pay = OT Hours × Rate × 1.5. Total Pay = Regular + OT. Example: 42 hours at $20/hour = (40 × $20) + (2 × $20 × 1.5) = $800 + $60 = $860. California additionally requires daily overtime after 8 hours per day and double time after 12 hours per day.
    What is the standard number of working hours per year?
    The standard full-time annual hours in the US is 2,080 hours (40 hours/week × 52 weeks). However, after accounting for paid holidays (~10 days = 80 hours) and typical vacation (10 days = 80 hours), actual hours worked are closer to 1,920 hours. Freelancers and consultants typically plan for 1,800 billable hours/year to account for non-billable administration, business development, and downtime. To convert hourly rate to annual: multiply by 2,080. To convert annual salary to hourly: divide by 2,080.
    How do I calculate break time from total hours?
    Net Work Hours = Total Elapsed Time − Total Break Time. Convert breaks to decimal hours first: 30 min = 0.50h, 45 min = 0.75h, 60 min = 1.00h. Example: Shift 8:00 AM to 5:30 PM (9.5 hours elapsed) − 45 min lunch (0.75h) − 15 min break (0.25h) = 9.5 − 1.0 = 8.5 net work hours. Under FLSA, short breaks under 20 minutes are paid, so they should NOT be deducted. Only deduct unpaid meal breaks (typically 30+ minutes where employee is fully relieved).
    How do I calculate pay from hours and minutes?
    First convert hours and minutes to decimal hours: Decimal = Hours + (Minutes ÷ 60). Then multiply by the hourly rate. Example: 7 hours 45 minutes = 7.75 decimal hours. At $22/hour: 7.75 × $22 = $170.50. For overtime: Regular Pay = min(total decimal hours, 40) × rate. OT Pay = max(0, total − 40) × rate × 1.5. Add both for total gross pay. Always use the decimal hours representation for any multiplication involving money — never multiply hours and minutes separately.
    What is the difference between elapsed time and work time?
    Elapsed time is the total clock time from when you arrived to when you left — including all breaks. Work time (or net work time) is the elapsed time minus any unpaid break periods. Elapsed: 8:00 AM to 5:00 PM = 9 hours. Work time after 30 min unpaid lunch: 8.5 hours. Payroll systems track work time for pay purposes. Time tracking apps like Toggl often track elapsed time and let you assign time to break categories. For payroll, ensure you are recording and being paid for work time, not elapsed time minus any additional deductions your employer shouldn't be taking.
    Real-World Calculations
    Six Work Shift Scenarios — Where This Calculator Saves Time
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    Hospital Shift Worker

    Night shift: 10:30 PM to 6:45 AM. Standard subtraction gives wrong answer (−3:45). This calculator handles overnight correctly: 8 hours 15 minutes. Minus 30-minute break: 7 hrs 45 min net = 7.75 hrs. At ₹320/hr: ₹2,480 earned.

    10:30 PM → 6:45 AM = 7h 45m
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    Freelance Developer

    Tracked 3 sessions: 9:15 AM–12:40 PM (3h 25m), 2:00 PM–5:30 PM (3h 30m), 7:45 PM–9:20 PM (1h 35m). Total: 8h 30m = 8.5 decimal hours. At $75/hr: $637.50 for the invoice. Manual addition of hours+minutes is where billing errors happen.

    3h25 + 3h30 + 1h35 = 8h30m
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    Factory Weekly Timesheet

    Mon 8h30m, Tue 9h15m, Wed 8h00m, Thu 9h45m, Fri 8h30m. Total: 44 hours. Standard hours: 40. Overtime: 4 hours at 1.5× rate. A common payroll error: adding 8+9+8+9+8=42 and forgetting the 30-minute and 45-minute fractions that add 2 more hours.

    44h total — 4h overtime
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    Flight Duration

    Departs 11:45 PM local (Day 1). Arrives 7:20 AM local (Day 2) — but crosses a time zone from IST (UTC+5:30) to SGT (UTC+8). Actual flight: 4h 5m. Time difference alone accounts for 2h 30m of the apparent 7h 35m clock difference. The Basic mode calculates local time elapsed; time zone adjustment is manual.

    Clock: 7h35m − TZ offset = 4h5m
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    Payroll Decimal Error

    Employee worked 7 hours 20 minutes. HR spreadsheet stores 7.20 instead of 7.333. Error: 0.133 hrs per shift. At $22/hr: $2.93/shift. Over 250 shifts/year: $732 underpaid. This specific error — treating HH:MM as a decimal directly — is one of the most common payroll calculation mistakes.

    7h20m = 7.333 hrs (not 7.20)
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    Restaurant Split Shift

    Lunch shift: 11:00 AM–3:30 PM (4h 30m). Break: 3:30 PM–5:00 PM (unpaid). Dinner shift: 5:00 PM–10:45 PM (5h 45m). Net paid time: 10h 15m = 10.25 hrs. Pay: 8h at base + 2.25h at overtime. The time card mode handles this multi-session shift correctly.

    4h30 + 5h45 = 10h15m paid
    Avoid These Errors

    5 Time Calculation Mistakes That Cost Workers and Businesses

    1
    Treating HH:MM as a decimal (the most expensive mistake). 7 hours 20 minutes is NOT 7.20 hours — it is 7.333 hours (20 ÷ 60 = 0.333). Multiplying 7.20 by an hourly rate gives a wrong answer. On a ₹400/hr rate: 7.20 × 400 = ₹2,880 (wrong). Correct: 7.333 × 400 = ₹2,933. The difference is ₹53 per shift — across 250 shifts a year at ₹13,250 underpaid. Always convert HH:MM to decimal before multiplying by rate.
    2
    Subtracting overnight times directly and getting a negative result. If a shift starts at 10:00 PM and ends at 6:00 AM, subtracting gives 6 − 22 = −16. The correct approach: either add 24 to the end time when it is earlier (6 + 24 = 30, then 30 − 22 = 8 hours), or convert both times to minutes-since-midnight (360 − 1320 = negative, so add 1440: 360 + 1440 − 1320 = 480 minutes = 8 hours). This calculator handles overnight automatically — but manual calculations must account for the date boundary.
    3
    Adding HH:MM columns in Excel without time formatting. If you type 8:30 into Excel without formatting it as a time value, Excel treats it as a text string or as 8 hours 30 minutes past midnight (0.354 of a day). Summing these values in a SUM() formula may give nonsensical results. Either use Excel time functions (=HOUR(A1)*60+MINUTE(A1) to convert to minutes, sum, then convert back) or use a dedicated time calculator to avoid format-related errors in spreadsheets.
    4
    Forgetting to deduct unpaid breaks from total shift time. A shift from 9:00 AM to 5:30 PM is 8.5 hours. But if 30 minutes of break is unpaid (as is standard in most Indian and international employment contracts), the payable hours are 8.0. Multiplying 8.5 by rate and paying for the break is an employer overpayment; failing to account for the break and paying 8.5 hours is worker-side incorrect time reporting. The Net Hours with Break mode handles this deduction precisely.
    5
    Rounding hours without a consistent rule — and always rounding in one direction. Many businesses round time to the nearest quarter-hour (15 minutes). This is legal if applied consistently and not always in the employer’s favour. A shift of 8h 7 minutes rounds to 8h 0m; a shift of 8h 8 minutes rounds to 8h 15m. The cutoff is 7.5 minutes. Rounding all fractions down (so 8h 14m becomes 8h 0m) violates wage laws in most jurisdictions. If you round, round to nearest — not always down.
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    Built & Maintained By
    Keeroot Solutions
    Digital Product Studio · Coimbatore, India · keeroot.com · Last updated: April 2026
    This Hour Difference Calculator is built and maintained by Keeroot Solutions. All five calculation modes handle the base-60 time arithmetic correctly — overnight shifts are handled by detecting when end time is less than start time and adding 24 hours, decimal conversion uses exact division (minutes ÷ 60) without premature rounding, and the weekly time card accumulates minutes before converting to avoid fraction errors. All calculations run locally in your browser — no time or pay data is stored or transmitted.
    ✅ Overnight shift support 💰 Pay calculator included 🔒 No data stored 📅 Updated April 2026
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