Time Since/Until Calculator
Pick a date/time
Tip: Press Enter in the field to calculate. The result updates to the second.
Result
About the Time Since/Until Calculator
This free tool lets you measure the exact amount of time between now and any chosen date/time, either in the past (since) or the future (until). It breaks the result into years, months, weeks, days, hours, minutes, and seconds, offering a clear and detailed picture of elapsed or remaining time.
The calculation is calendar-aware, meaning it accounts for the actual number of days in each month and leap years. This ensures that month and year counts match real-world dates instead of relying on rough day-based averages. The interface uses a built-in date/time picker for fast, accurate input, and the result updates instantly on click.
All computations happen entirely in your browser, using JavaScript to compare your selected date/time with your device’s clock. This guarantees privacy—your chosen dates are never uploaded to a server or stored anywhere online. Whether you’re tracking time since a milestone (birthday, project start, historical event) or counting down until an upcoming occasion (exam, launch day, anniversary), the tool works offline once loaded.
FAQs
How is it calendar-aware?
We step year-by-year and month-by-month from the earlier date to the later one. That respects real month lengths and leap years.
Does DST affect results?
No. Internally, the calculator works with UTC-equivalent timestamps derived from your local input, avoiding DST drift.
Can I share a prefilled link?
Yes—use Share link. It adds ?t=YYYY-MM-DDTHH:mm to the URL, which the page reads on load.