What does the Time Since/Until Calculator do?

It calculates the exact duration between now and a specific date/time in years, months, weeks, days, hours, minutes, and seconds.

How accurate is the calculation?

The tool is calendar-aware for months/years and precise to the second.

Is my date/time data private?

Yes. All processing happens in your browser. No date or time values are sent to any server.

Can it calculate future as well as past dates?

Yes. It automatically detects whether your date is in the past or future and shows 'since' or 'until' accordingly.

Time Since/Until Calculator – Exact Duration Between Dates

Time Since/Until Calculator

Calculate the duration in years, months, weeks, days, hours, minutes, and seconds since or until a specific event.

Select Date and Time of Event:

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

What does this tool calculate?

It shows the precise time between now and a specific date/time, down to seconds, with a human-readable breakdown.

Can it handle both past and future dates?

Yes. It detects whether your date is in the past (since) or future (until).

How accurate is it?

Months and years are calculated with actual calendar rules, and the result is accurate to the second.

Is my data private?

Completely. All calculations are performed locally on your device without sending anything over the internet.

⭐ Starlight Tools / Time Since/Until Calculator