Date and Time Difference Calculator Online — Free
Runs 100% in your browser — your files never leave your device.
"How long until…" and "how long since…" deserve exact answers, not calendar finger-counting. Pick two dates and times and get the gap broken into days, hours, minutes, and seconds — plus the raw total in seconds. The order of the two dates does not matter; the difference is always positive.
How it works
- 1
Pick the first date and time
Use the date-time picker or type directly into the field.
- 2
Pick the second
Either order works — the gap is computed as an absolute difference.
- 3
Read the breakdown
Days, hours, minutes, seconds — and the total seconds for good measure.
About this tool
What the difference gives you
Enter two dates and times and the tool reports the gap in every useful unit at once — total days, hours, minutes, and seconds, plus the calendar breakdown. No counting on knuckles, no forgotten month lengths.
The boundary questions it answers
Project deadlines (how many working-feel days until launch), age in exact days, subscription periods, contract durations, and the classic "how long since" questions. The total-days figure is the one that survives timezone confusion best — calendar breakdowns depend on where the dates sit.
Order does not matter
Enter the later date first or the earlier one first — the difference is the same absolute gap either way. The tool computes the span, not a direction.
Frequently asked questions
Does the calculation account for leap years?
Yes — the difference is computed on real calendar dates, so February 29s count where they occur.
Why do the calendar breakdown and total days disagree slightly?
Calendar units (months, years) vary in length — a "month" is 28 to 31 days. Total days is the exact physical gap; the calendar breakdown is the human-friendly approximation.
Can I include times of day?
Yes — add times to both dates and the gap measures down to the second.