Date & Time Tools

Calculate age, date differences, work hours, overtime, and time zones—built for leap years and DST. Everything runs in your browser; your dates never leave your device.

25 Free Date & Time Tools
Handles leap years & DSTNo signup neededRuns in your browser

25 Available Tools

D

Daily Work Hours Calculator

Calculate net hours for one shift from clock-in, clock-out, and unpaid breaks. Decimal output for daily timesheets. Runs locally — no upload.

M

Monthly Work Hours Calculator

Free monthly work hours calculator: sum decimal weekly totals or estimate month-end hours. Runs locally—never uploaded.

A

Age Calculator

Free age calculator — enter your date of birth to find your exact age in years, months, weeks, and days. See your next birthday countdown and number of days lived. No signup.

A

Age on Other Planets

Free age on other planets calculator — find your age on Mars, Venus, Mercury, Jupiter, Saturn, Uranus, Neptune, and Pluto based on each planet's orbital period. No signup.

B

Break Time Calculator

Free break time calculator — enter start time, end time, and total break duration to instantly calculate net work hours for the day. Great for timesheets. No signup.

D

Date Calculator

Free date calculator — add or subtract days, weeks, months, or years from any date. Find future or past dates for deadlines, project planning, and events. No signup required.

E

Employee Hours Tracker

Free employee hours tracker — log start/end times, breaks, and overtime for multiple employees. Calculate weekly totals and prepare payroll summaries. No signup required.

F

Freelance Hours Calculator

Free freelance hours calculator — log start and end times for multiple projects to calculate total billable hours and estimate earnings at your hourly rate. No signup.

H

Hours Calculator

Free hours calculator — calculate the total time between any two times, including overnight spans. See results in hours and minutes or decimal format. No signup required.

H

Hours Calculator with Break

Free hours calculator with breaks — enter start time, end time, and break duration to calculate net work hours. Perfect for payroll and timesheet accuracy. No signup required.

O

Overtime Hours Calculator

Free overtime hours calculator — enter daily hours worked and your regular schedule limit to calculate total overtime hours. Supports daily and weekly overtime rules. No signup.

P

Pet Age Calculator

Free pet age calculator — convert your dog or cat's age into equivalent human years using breed-adjusted formulas. Great for understanding your pet's life stage. No signup.

P

Planet Distance Converter

Free planet distance converter — convert between astronomical units (AU), kilometers, and miles for solar system distances. See how far each planet is from the Sun. No signup.

P

Planet Size Comparison

Free planet size comparison — compare the diameter, mass, surface area, and volume of all planets relative to Earth. See scale ratios with accurate data from NASA. No signup required.

P

Planetary Day Converter

Convert Mars sols into Earth days and compare planetary day lengths instantly. Fast, accurate, browser-based, and free to use.

P

Planetary Year Converter

Convert Earth years to orbital years for all planets. A Mars year is 1.88 Earth years; a Neptune year is 165 Earth years. Browser-based, no signup, uses NASA IAU orbital data.

S

Shift Hours Calculator — Day, Evening & Overnight Shifts

Calculate day, evening, or overnight shift hours with break deductions. Runs locally in your browser—never uploaded. Free for nurses and shift workers.

S

Sunrise & Sunset on Other Planets

How long does daylight last on Mars, Venus, or Jupiter? Explore sunrise and sunset times based on each planet's rotation period and axial tilt. Browser-based, no signup.

T

Time Calculator

Free time calculator — add or subtract hours, minutes, and seconds, or calculate the exact duration between two times. Handles overnight spans automatically. No signup required.

T

Time Converter

Convert seconds, minutes, hours, days, weeks, and years instantly with live multi-unit calculations and accurate results.

T

Time Duration Calculator

Free time duration calculator — calculate the exact duration between two dates or times in days, hours, minutes, and seconds. No signup required.

T

Time Zone Converter

Free time zone converter — convert any time between world cities and time zones. Compare multiple zones at once. Perfect for scheduling international meetings. No signup.

T

Timesheet Calculator

Free timesheet calculator — log daily work hours and breaks for a full week, calculate total regular and overtime hours, and prepare a payroll-ready timesheet. No signup.

U

Unix Timestamp Converter

Free Unix timestamp converter — convert epoch timestamps to readable dates and back. Supports seconds and milliseconds. Essential for API debugging and logging. No signup.

W

Weight on Other Planets

How much would you weigh on Mars (38% of Earth), Jupiter (2.5×), or the Moon (16.5%)? Free weight on other planets calculator using NASA surface gravity values. No signup.

Free date and time calculators find exact age, days between dates, net work hours with breaks, time zone conversions with DST, and decimal hours for payroll—all in your browser with no upload to a server.

Calculate Dates & Times Free — Instant Results

Pick any tool below, enter your values, and copy the result in seconds.

No signup · Local processing · Leap years & DST aware

By Muhammad Abdullah Rauf · Founder, EverydayTools.proUpdated 2026

What are date and time tools?

Date and time tools calculate ages, days between dates, durations, work hours, overtime, and time zone conversions—handling leap years, month lengths, and daylight saving time in your browser.

Date and time tools answer everyday calendar and clock questions that are easy to get wrong by hand: exact age from a birth date, days until a deadline, net hours after lunch, or what time a meeting is in another city.

Good calculators use real calendar rules—February in leap years, varying month lengths, and IANA time zones so DST shifts apply on the correct date. Work-hours tools convert clock times to decimal hours (7:30 = 7.5) for timesheets.

EverydayTools runs these calculators in your browser. Dates of birth, schedules, and shift times are not uploaded to our servers.

Pick the tool for your task—age, date math, duration, time zones, or work hours—then copy decimal or calendar results into forms and payroll.

Quick answers

Concise answers for common searches — definitions, steps, and comparisons.

Are date and time tools private?

Yes. Calculations run in your browser. Birth dates, schedules, and shift times are not uploaded to EverydayTools servers.

How do I convert 7:30 to decimal hours for payroll?

Decimal hours = 7 + (30 ÷ 60) = 7.5—not 7.30, which would mean seven hours and eighteen minutes.

Date Calculator vs Time Duration Calculator?

Date Calculator adds or subtracts calendar days/weeks/months. Time Duration Calculator measures elapsed time between two timestamps including hours and minutes.

How to use Date & Time Tools

  1. Choose the right calculator

    Age, date difference, add/subtract dates, time duration, time zones, daily work hours, or weekly timesheets.

  2. Enter dates and times

    Use pickers or type values. Include time-of-day when you need hour/minute precision.

  3. Check edge cases

    Confirm DST for zone conversions and whether breaks are paid or unpaid for work hours.

  4. Copy the result

    Paste into forms, payroll notes, project plans, or calendar invites.

Who uses Date & Time Tools?

Common real-world scenarios where this tool saves time.

HR and payroll

Net work hours, overtime splits, and weekly totals for timesheets and compliance checks.

Project and contract timelines

Days between milestones, warranty windows, and add/subtract days from a start date.

Remote team scheduling

Convert meeting times across zones without DST mistakes when US and EU shift on different weeks.

Forms and applications

Exact age in years, months, and days for visa, insurance, and government forms.

Workflow guides

Step-by-step chains that connect related tools for common tasks.

Weekly timesheet workflow

  1. Log each shift with Daily Work Hours or single-day mode on Work Hours Calculator.
  2. Switch to weekly mode to sum regular and overtime hours.
  3. Optional: Timesheet Calculator for multi-employee rows.

International meeting

  1. Pick source zone, time, and target zone in Time Zone Converter.
  2. Use the meeting date—not today—so DST rules apply correctly.
  3. Copy converted time into the calendar invite.

Date & Time Tools examples

Days between two dates

Input

Start: 2026-05-01, End: 2026-06-15

Output

45 calendar days (with week/month breakdown)

Date difference tools handle month boundaries and leap years automatically.

Net work hours after lunch

Input

Start 9:00 AM, End 5:30 PM, Break 45 min

Output

7.75 decimal hours

Subtract unpaid breaks before multiplying by an hourly rate.

Time zone for a meeting

Input

2:00 PM America/New_York → Europe/London on 2026-11-05

Output

Converted time reflects DST rules for that date

Offsets change during DST—always convert using the meeting date.

How these calculators work

Calendar math uses date-aware arithmetic. Time zones use IANA rules per selected date. Work hours convert to minutes, subtract breaks, then output hh:mm and decimal hours.

Reference tables

Which date & time tool should I use?

Match your task to the calculator on this hub.

ToolBest forUse when…
Age CalculatorYears, months, days from DOBForms, milestones, leap-year birthdays
Date CalculatorAdd/subtract calendar unitsDeadlines, warranties, 90-day windows
Time Duration CalculatorElapsed hours/minutesBilling blocks across timestamps
Time Zone ConverterGlobal meetingsDST-aware conversion for a specific date
Daily Work HoursOne shift net hoursClock-in, clock-out, unpaid breaks
Work Hours CalculatorDaily + weekly + OTFull timesheet and pay estimate

Calendar days vs business days

MethodCountsTypical use
Calendar daysEvery day including weekendsContracts, age, shipping windows
Business daysWeekdays only (tool-specific)SLAs, court deadlines, bank processing
Decimal hoursFraction of an hourPayroll multiply by hourly rate

Common mistakes to avoid

Troubleshooting

Time zone conversion off by one hour

Likely cause: DST or wrong date used for conversion.

Fix: Re-run with the meeting date and correct IANA zones (e.g. America/New_York).

Work hours total looks wrong

Likely cause: Unpaid breaks not deducted or overnight shift not handled.

Fix: Enter break duration; overnight shifts add 24h to end automatically.

Age differs from a form

Likely cause: Form may use age at last birthday vs exact years/months/days.

Fix: Match the format requested and confirm the reference date.

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Frequently Asked Questions

What's the easiest way to calculate days between two dates?

Use the Date Calculator—it counts exact calendar days and handles month boundaries and leap years.

Do date calculators handle leap years?

Yes. February 29 and cross-year spans are included automatically in age and difference tools.

Why is my meeting time conversion off by 1 hour?

Daylight saving time changes offsets by date. Convert using the meeting date and correct IANA time zones.

How do I convert hh:mm to decimal hours for payroll?

Decimal hours = hours + (minutes ÷ 60). Example: 7:45 = 7.75 hours.

Do work-hours tools subtract breaks?

Yes. Enter unpaid break minutes; net time is returned in hh:mm and decimal hours.

Are these date and time tools free?

Yes—free with no signup and no usage limits on this hub.

Is my data uploaded to a server?

No. Calculations run locally in your browser on your device.

Date Calculator vs Time Duration Calculator?

Date Calculator for calendar add/subtract. Time Duration for precise elapsed time between two timestamps.

Can I calculate weekly work hours and overtime?

Yes—use Work Hours Calculator weekly mode or related timesheet and overtime tools linked from this hub.

Which tool for exact age on a form?

Age Calculator returns years, months, and days from date of birth, including February 29 handling.

Privacy, accuracy, and trust

Privacy

Date and time tools on this hub run in your browser. Birth dates, schedules, and shift times are not uploaded to EverydayTools servers.

Accuracy

Calendar math uses leap years and real month lengths; time zone tools apply DST for the date you select.

Results are for convenience. For payroll, compliance, or legal deadlines, verify with official policy and local rules.

More free tools for the same workflow.

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Reviewed by EverydayTools Editorial Team on 2026-05-20.