Date and time difference
Date and time difference lets you calculate elapsed milliseconds, seconds, and duration between instants in your browser.
Duration converter
Duration converter lets you convert seconds and ISO 8601 durations without treating months or years as fixed seconds in your browser.
Duration converter
⌂ Inputs and results stay in this browser and are not automatically stored or sent.
Waiting for input
Input
Durations containing years or months are not converted to total seconds without a reference date.
Output
Waiting for input
Complete text result
How to use
Enter an ISO duration such as PT1H30M or seconds and select the conversion direction. A duration is not a timestamp.
P1M is a month, while PT1M is a minute. Years and months cannot be reduced to fixed seconds without calendar context; do not replace a rejected month with an assumed 30 days.
Examples
PT1H30M15SPrinciples and limits
Each input is limited to 1,048,576 bytes, output to 33,554,432 bytes, and processing to 5,000 ms. Input is never silently truncated.
Guides
Related tools
Unix time converter
Unix time converter lets you convert explicit epoch seconds or milliseconds to UTC and IANA time in your browser.