Time Difference & Work Hours Calculator

Time Duration & Timesheet Studio Pro

Precisely measure duration between two timestamps, handle cross-midnight overnight shifts effortlessly, deduct lunch breaks, calculate payroll decimal hours, and compute work earnings 100% Client-Side.

Quick Presets:

1. Start Time

24-Hour Format

2. End Time

+1 Day (Overnight) 24-Hour Format

3. Break Deduction

Custom: mins

Hourly Wage Calculator (Optional)

Enter your hourly rate to automatically calculate total earnings

Total Net Duration (Cross-Midnight)

h m

Payroll Decimal Hours:

Estimated Gross Earnings:

hrs × /hr

Total Minutes

Total Seconds

Weekly Timesheet Table (Mon - Sun)

Day	Start	End	Break (m)	Hours	Decimal

Total Week Hours

Regular (Max 40h)

Standard

Overtime (OT)

1.5x rate

The Cross-Midnight Shift Conundrum & Payroll Decimal Hours Dilemma

Whether calculating billable hours for freelance clients from 08:30 AM to 05:15 PM with a 45-minute lunch break, or logging medical night shifts from 10:00 PM to 06:00 AM next morning, accurate time calculation is vital for fair compensation.

Conventional web calculators routinely fail at two critical points: first, they produce negative numbers when an overnight shift crosses midnight (since 06:00 < 22:00); second, they only output text such as "7 hours 45 minutes". Payroll engines and spreadsheet formulas cannot multiply hourly rates directly by minutes—they require decimal hours like 7.75 hrs (as 45 / 60 = 0.75).

Time Duration & Timesheet Studio Pro by PhuDuy Tools solves this natively: automated cross-midnight modulo arithmetic, dedicated break deduction, instant decimal conversion for Excel formulas, real-time earnings estimator, and a 7-day weekly timesheet with one-click CSV export.

3 How to Calculate Time Duration & Work Hours in 3 Steps

Set Start & End Times

Enter start and end times in 24h format or click Now. The engine automatically handles shifts rolling past midnight into the next morning.

Deduct Breaks & Set Rate

Select unpaid lunch or rest break duration (30m, 45m, 60m) and optionally enter your hourly wage to monitor gross compensation.

Review Decimal Hours & Export

Inspect both Hours:Minutes and payroll decimal hours. Copy with 1 click directly into Excel or open the Weekly Timesheet tab for CSV export.

Payroll Conversion Reference: Minutes to Decimal Hours

Official accounting standard converting elapsed minutes into decimal fractions for precise salary multiplication:

Elapsed Minutes	Decimal Hours	Mathematical Formula	Practical Shift Example
15 phút	0.25 giờ	15 / 60 = 0.25	Tăng ca 15 phút sau giờ hành chính
30 phút	0.50 giờ	30 / 60 = 0.50	Nửa tiếng làm việc hoặc nửa ca phụ
45 phút	0.75 giờ	45 / 60 = 0.75	Ba phần tư giờ công tiêu chuẩn
60 phút	1.00 giờ	60 / 60 = 1.00	Trọn vẹn một giờ công lao động
7 giờ 45 phút	7.75 giờ	7 + (45 / 60) = 7.75	Ca hành chính 8h30-17h00 (nghỉ 45p)

Why PhuDuy Tools Leads the Time Duration Industry

Automated Cross-Midnight Engine

Zero negative hour errors when end time is earlier than start time. Modulo 1440-minute mathematics seamlessly computes overnight night shifts.

Dual Format: Clock & Payroll Decimals

Outputs both human-friendly clock duration (7h 45m) and accounting decimal hours (7.75h) with 1-click clipboard instant copy.

Instant Gross Wage & Earnings Estimator

Multiply work hours by your custom hourly rate across multiple currencies (USD, VND, EUR) to see real-time compensation.

Weekly Timesheet & 1-Click CSV Export

Log work intervals across all 7 days with automatic 40-hour overtime splitting and zero-lag CSV table generation for accounting.

Frequently Asked Questions About Time Tracking & Payroll

Why do accountants and payroll software require decimal hours? ▾

Formulas and payroll databases cannot perform arithmetic directly against clock formats like "7h 30m". Because hours contain 60 minutes, 30 minutes converts to 30 / 60 = 0.50 decimal hours (resulting in 7.50 hrs), which can then be multiplied directly by wage rates.

How does the calculator handle overnight shifts crossing midnight? ▾

The engine uses automatic midnight threshold detection: whenever the end time is numerically lower than the start time, it recognizes an overnight shift and adds 24 hours (1440 minutes) to the end timestamp, ensuring completely flawless duration tracking without cumbersome date pickers.

How is overtime (OT) pay calculated and regulated? ▾

Under standard employment labor laws, overtime beyond the regular 40-hour weekly threshold is compensated at a minimum of 1.5x regular pay (time-and-a-half). Weekend and public holiday shifts often qualify for 2.0x to 3.0x premium penalty rates.

Is unpaid lunch break time legally counted towards working hours? ▾

At most enterprises and organizations, lunch and meal breaks (30 to 90 minutes) are considered non-working rest intervals and excluded from compensated wage hours unless explicitly designated as paid on-duty breaks in employment contracts.

Are my timesheet records and wage rates securely kept private? ▾

100% Client-Side Privacy Guarantee. All timestamp calculations, wage formulas, and timesheet records execute exclusively in your local browser memory. Zero analytics, zero cloud logging, zero telemetry.

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