✅ 100% Free — No sign-up ⚡ 4 calculators in one suite 🔒 All calculations run in your browser 💾 Session history auto-saved

Date Duration Time Accumulator Date Offset Decimal Converter

How to Use Each Calculator

Date Duration: Enter start and end dates to calculate total days, hours, and minutes. Use for project timelines, billing periods, or tenure calculations.
Time Accumulator: Add multiple time blocks together (e.g., 2h 30m + 1h 15m + 45m). Perfect for summing work hours across projects.
Date Offset: Add or subtract days from a date. Example: What date is 30 days from today?
Decimal Converter: Convert decimal hours (e.g., 2.5) to time format (2h 30m) for payroll systems.
Session History: Your recent calculations are saved in the sidebar — click any result to restore it.

Start Date

End Date

Total Duration

—

Years

—

Months

—

Days

—

Calendar Days

—

Working Days

—

Weekend Days

Stack time entries — e.g. project tasks for billing

Running Total 0h 00m

Total Hours

Total Minutes

0.00

Decimal Hours

Start Date

Operation

Amount

Unit

Milestone Date

—

Convert hours & minutes to decimal format for invoicing and billing systems.

Hours

Minutes

Hourly Rate (optional)

Quick reference: 15m = 0.25 · 30m = 0.50 · 45m = 0.75 · 1h 30m = 1.50 · 2h 15m = 2.25 · 7h 30m = 7.50

About the Time & Date Calculator Suite

BizTimeCalculator bundles four calculators freelancers, HR teams, and project managers use regularly: date duration, time accumulation across multiple entries, date offset (adding or subtracting days from a date), and decimal-to-time conversion for accurate billing. All calculations run instantly in your browser.

Where This Gets Used

Freelancers converting logged hours and minutes into decimal format for accurate invoicing. HR teams calculating exact tenure or working days between two dates for payroll. Project managers adding buffer days to a deadline and needing the resulting date instantly, without counting on a calendar by hand.

Frequently Asked Questions

What's the Time Accumulator for? It's for adding multiple separate time blocks together — useful when you've logged several work sessions across a day or week and need the total.

Does the Date Duration calculator count weekends? By default it counts all calendar days; check the working-days-only option if you need business days specifically.

How does the Decimal Converter work? It converts hours and minutes (like 2 hours 15 minutes) into decimal format (2.25) for billing systems that require decimal hours.

Is there a limit on date ranges? No — calculate durations spanning days or decades, whatever your use case requires.

Advanced Time & Date Analytics Suite