Calculate days, months and years between two dates.
Updated
Quick start
Pick a From and To date, read the calendar diff plus raw totals — all in your browser.
Use the date pickers to choose start and end. The tool defaults to today and 30 days out.
Calendar diff (years / months / days) plus total days, weeks, business days, hours, minutes, seconds.
Use the second panel to push a base date forward or back by years / months / days — useful for finding deadlines.
In-depth guide
Calculate the difference between any two dates as calendar years/months/days, then see raw totals — days, weeks, business days, hours, minutes, seconds. Add or subtract years, months and days from a base date to find a future or past date.
'2 years 3 months 14 days' is what you'd say in conversation. '839 days' is what a spreadsheet computes. Both are correct — they answer different questions.
When to reach for it. Use it for elapsed days between dates, deadline counting, and age-in-days style questions.
When something else is better. It works in plain calendar dates; it won’t apply business-day rules, holidays or time-zone-sensitive cutoffs unless you account for them yourself.
The pitfall to watch. Inclusive vs exclusive counting is the usual confusion — decide up front whether both endpoints count before you trust the total.
Everything runs on your device. The values you enter are processed locally in this browser tab — EpitomeTool does not send your input to a server, store it, or log it. That means you can use the tool offline once the page has loaded, and refreshing the tab wipes the slate.
No. All math runs in your browser using the JavaScript Date API. Works offline once the page is loaded.
Calendar-aware: we walk from the start date and increment years, then months, then days, borrowing days from the previous month when needed. That matches how people naturally count age and tenure.
Monday through Friday in the from-date's local timezone. Holidays are not subtracted — they vary by country and would need a holidays library.
Months are variable-length, so 'total months' is ambiguous — we don't show it. Total weeks is total days ÷ 7, which can produce a fraction. Total days is always an integer.
Adding one year to Feb 29 2024 lands on Feb 28 2025 — JavaScript's Date.setFullYear clamps to the last valid day of the month. Same for end-of-month additions (Jan 31 + 1 month = Feb 28/29).
Date pickers send local-date strings, and the math uses local midnight for each day, so the result reflects your timezone consistently.
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