Giga Useful ToolsData
Date calculator
Difference between two dates, or add/subtract days, weeks, months or years.
Everything runs in your browser. No file is ever uploaded to a server.
- 1Choose 'Date difference' to compare two dates, or 'Add or subtract days' to shift one date.
- 2In difference mode, pick a start and end date with the date pickers. The breakdown updates instantly.
- 3In add/subtract mode, pick a base date, type an amount (negative to subtract), and choose the unit (days, weeks, months, years).
- 4Read the resulting date or the year/month/day breakdown in the highlighted box.
How does the date difference handle years and months, not just days?+
It breaks the gap down into years, months and days the way a calendar would (walking forward month by month rather than doing rough day division), plus it always shows the total number of days too. So you get both '2 years, 3 months, 14 days' and '838 days' from the same two dates.
What happens if I pick an end date earlier than the start date?+
The calculator still works. It swaps the dates internally to compute the difference and adds a note letting you know the first date is actually later than the second, so the numbers aren't misread as negative.
Can I subtract time instead of adding it in the 'add or subtract' mode?+
Yes. Type a negative number in the amount field (e.g. -30) with any unit (days, weeks, months, years) and it'll count backward from your base date instead of forward.