Advanced Date & Age Calculator
Four focused tools for date arithmetic: difference between two dates, add or subtract time, age and birthday countdown, and workday projection with weekend and Indonesian holiday exclusions. All math runs locally with the native Date object — no libraries, no uploads.
Date Difference
From / To · optional exclusionsHow to use
Pick the tab that matches your task, fill in the dates, and press Calculate. Each tab has a Load sample button that fills realistic example data so you can see the math immediately.
- Choose a tab — Date Difference, Add / Subtract, Age Calculator or Workday Projector.
- Fill the inputs — type or pick dates; toggle exclusions like weekends or holidays if relevant.
- Press Calculate — results render in a grid with the high-value number highlighted in red.
- Load sample — instantly fills realistic example data (e.g. birth date 1995-06-15) if you want to see the math first.
- Copy results — copies a plain-text summary to your clipboard so you can paste it anywhere.
What it computes
Date Difference
Years, months, days, total days, weeks, hours and minutes between two dates. Optional weekend and Indonesian holiday exclusions.
Add / Subtract
Project any date forward or backward by days, weeks, months or years. Handles month-end clamping (e.g. Jan 31 + 1 month = Feb 28).
Age & Birthday
Exact age in years/months/days, day of week born, total days and hours lived, plus next-birthday countdown.
Workday Projector
Add N business days to a start date, skipping Saturdays and Sundays and the bundled Indonesian public holiday list.