Free date & time calculators — instantly
Quickly find “what time was X hours ago”, calculate date differences, add or subtract time, convert timestamps, and more. Results show UTC and update live to your local time.
Quick calculator
Popular tools
Time Ago Calculator
Find the exact date/time X seconds/minutes/hours/days/weeks/months/years ago.
Add / Subtract Time
Add or subtract multiple units (years, months, days, hours, minutes, seconds) to any date.
Quick examples
Common queries you can open directly:
Why use datetimecheck?
Calculating dates and times by hand is error-prone — different months have different lengths, leap years exist, and timezones complicate everything. datetimecheck gives you precise answers based on UTC and converts them live to your local time. Use it for scheduling, debugging logs, timestamp conversions, or just satisfying curiosity.
Tips
- Use the calculators to convert server timestamps to your timezone.
- Enter fractional values for partial units (e.g. 1.5 hours → 1 hour 30 minutes).
- Prefer canonical URLs for sharing (the tool redirects to canonical form automatically).
FAQ
How accurate are months and years?
Months and years are calculated using calendar-aware arithmetic: integer months/years apply calendar shifts (so Feb 28 → Mar 28), fractional months/years are converted to days based on the relevant month/year length for better accuracy.
Do calculations use my device time?
Server calculates the canonical UTC moment and caches it. Your browser converts that moment to local time live, so you see a ticking local result synchronized to your device.
Can I copy the result?
Yes — use the "Copy result" button on result pages. The homepage quick calculator redirects to the canonical page which has a copy button.