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Calculator Tools

Date & Time Calculator

Calculate time differences, days between dates, business days, age, and countdown timers. Perfect for project planning, scheduling, and time management.

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Calculation Mode

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Start & End Date/Time

Quick Presets

Powerful Features

Real-time Calculations
Updates instantly as you type
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Business Days
Exclude weekends & holidays
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Age Calculator
Precise age calculations
Countdown Timers
Time remaining to events
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Copy to Clipboard
One-click result copying
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Multiple Modes
Date, time, age, countdown
Quick Presets
Common calculations ready
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Responsive Design
Works on all devices

📖 Usage Examples

Project Planning:
Calculate days between project start and deadline, including business days.
Age Calculation:
Find exact age in years, months, and days from birth date.
Time Tracking:
Calculate hours worked between start and end times.
Event Countdown:
Count down to important dates like holidays or deadlines.
Overview

Date & Time Calculator — Differences, Age & Countdown

The Date & Time Calculator on sourcecodestack computes the exact duration between any two points in time, entirely in your browser. Switch between five modes — Date & Time, Date Only, Time Only, Age Calculator, and Countdown — to get the specific breakdown you need. Results update instantly as you type, showing years, months, days, hours, minutes, and seconds alongside a total-seconds summary.

The calculator also supports business-day filtering: toggle the Business Days switch to exclude weekends from the count, and configure whether your working week starts on Monday or Sunday. Quick Presets let you load common scenarios like time remaining until midnight, a 7-day difference, an age calculation from a birth date, or a New Year countdown with one click.

100% freeNo sign-upRuns in your browserReal-time results
How to use it
  1. 1Select a calculation mode: Date & Time, Date Only, Time Only, Age Calculator, or Countdown.
  2. 2Enter your start and end dates and/or times using the date and time input fields.
  3. 3Read the result immediately in the right-hand panel — no submit button needed.
  4. 4Enable Business Days Only to filter weekends and set your custom work-week boundaries.
  5. 5Click Copy Result to copy the calculated duration to your clipboard.
Key features
  • Five calculation modes: full datetime difference, date-only, time-only, age, and countdown
  • Breaks down results into years, months, days, hours, minutes, and seconds simultaneously
  • Business-days mode excludes weekends, with configurable work-week start and end day
  • Results recalculate instantly on every input change — no button click required
  • Quick Presets for common use cases: now-to-midnight, week difference, age, New Year countdown
  • Copy result to clipboard in a formatted human-readable string
  • All calculations run locally in your browser with no data sent anywhere

Frequently asked questions

How does the Age Calculator mode work?
Select Age Calculator, enter a birth date as the start and today as the end, and the tool shows the exact age in years, months, and days.
What does the business-days count exclude?
By default it excludes Saturday and Sunday. You can configure the work week to start on Sunday or Monday and end on Friday or Saturday to match different regional or company calendars.
Can I calculate time differences that cross midnight?
Yes. The Time Only mode handles differences that cross midnight by adding 24 hours to the result when the end time is earlier than the start time.
Does the calculator account for leap years?
Years are computed using calendar arithmetic, so leap years are handled correctly when calculating date differences across February 29.