Time Between Dates
Find exact durations, adjust dates by hours and minutes, track work shifts, convert time zones, and count down to any moment — all in your browser.
More calculators
Companion tools that run entirely in your browser.
Time math without spreadsheets
Project deadlines, payroll hours, international meetings, and event countdowns all need reliable time arithmetic. These tools handle the calculations so you can focus on planning.
Built on web standards
Time zone conversion uses the browser Intl API — the same engine your operating system relies on for locale-aware dates.
Frequently asked questions
How is duration between two dates calculated?
We take the absolute difference in milliseconds between the two Date objects, then break it into days, hours, minutes, and seconds.
Which time zones are supported?
We list all IANA zones from Intl.supportedValuesOf("timeZone") when your browser supports it — hundreds of global zones.
Does the countdown work offline?
After the page loads, the countdown runs locally with setInterval. No server polling is required.
Are my dates stored?
No. Your dates and times never leave your device.