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What is it?

This tiny utility library simplifies TTL math and date calculations (typically for... TTL math). Ever find yourself adding things like this to your API code?

60 * 24 * 30 * 6 // expire in 6 months

Yeah? We do too.

Now you don't have to. This library has only two primary tasks:

1. Getting the number of seconds from a human-readable string duration:

This is useful when creating max-age headers, TTL for cache-expirations, etc. We literally use this all the time.

getSeconds('1 day, 4 hours, and 36 minutes') // 102960

2. Adding durations to dates:

Sometimes you need the actual expiration date, not just the TTL (seconds). This function does that thing.

datePlus('2 months') // 2022-12-23T00:11:58.534Z

...or other dates

datePlus('2 months', datePlus('5 months'))

Ok, we lied... it has one more use:

3. Dividing durations!

This has limited use, we admit - but sometimes you need to create time batches, or figure out how many X in a Y. The cool thing is, each duration is parsed to the second, allowing complicated durations to be divided by complicated durations. Well, we think it's cool anyway!

divide('1 day').by('3 hours') // 8


import { getSeconds, divide, datePlus } from 'itty-time'

// Easily get TTL in seconds
getSeconds('3 hours') // 10800

// Complicated bits?  No problem.  (Oxford comma optional)
getSeconds('1 day, 4 hours, and 36 minutes') // 102960

// Need an expiration date?
datePlus('5 seconds') // 2022-10-22T23:10:11.824Z
datePlus('1 minutes') // 2022-10-22T23:11:06.824Z
datePlus('2 months') // 2022-12-23T00:11:58.534Z
datePlus('4 years') // 2026-10-22T23:11:58.534Z

// Add time to other dates
datePlus('4 years', datePlus('2 years')) // 2028-10-22T23:11:58.534Z

// Want to find out how many X are in Y?
divide('1 week').by('days') // 7
divide('2 minutes').by('seconds') // 120
divide('3 days').by('hours') // 72
divide('1 day').by('3 hours') // 8
divide('1 week').by('seconds') // 604800
divide('24 hours').by('minutes') // 1440
divide('3 days').by('hours') // 72
divide('1 day, 30 minutes').by('hours') // 24.5