The simplest way to measure
the time between any two moments.
SpanBetween is a free, no-signup time interval calculator. Pick any two points in time — or use the live "Now" anchor — and instantly see exactly how far apart they are.
How to calculate the time between two dates
Most calendar apps tell you what day it is. SpanBetween tells you how long it's been — or how long until. Set a start date on the left and an end date on the right, and the span is calculated instantly in days, hours, minutes, and seconds.
Toggle either side to "Now" and the display becomes a live clock — shrinking if you're counting down to a future date, growing if you're counting up from a past one.
Set your start date
Enter a specific date and time, or leave it pinned to "Now" to measure time elapsed from this moment.
Set your end date
Pick a future date for a countdown, or a past date to see how much time has passed. Set it to "Now" to measure time since any historical moment.
Choose your view
Switch between Days · Hrs · Min · Sec, Hours · Min · Sec, Minutes · Sec, or a single raw seconds readout.
Share it
Copy a link that encodes your exact settings, or email the interval directly from the app. Recipients see the same dates and span when they open it.
Common uses for a time interval calculator
Whether you need a countdown, want to measure time elapsed, or need to calculate work duration, SpanBetween handles it in one place.
Event countdowns
How many days until a wedding, product launch, vacation, or deadline? Set the right date and watch the gap shrink in real time.
Measure time since
How long since a project started, a contract was signed, or a habit began? Pin the right side to "Now" and the count-up grows automatically.
Calculate work duration
Need to know how many hours and minutes between a start and end time? SpanBetween gives you the exact interval down to the second.
Days between two dates
Planning a project timeline, calculating an age, or checking a lease term? Pick any two dates for an immediate, precise difference.
No account required. No ads. Just the math.
SpanBetween is a single-page tool — nothing to install, no data stored, no sign-up. All calculations happen locally in your browser. Share links encode the state in the URL itself, so nothing is ever sent to a server.