United Income at Capital One created this project with the intention of it helping us with timezone handling. We no longer use this project and it has not gained wide adoption. As such, we have stopped providing updates to this project and archived it as of June 28th, 2021.

local-crontab

A NodeJS library and utility to convert a crontab in a local timezone into a set of UTC crontabs. It creates multiple UTC crontabs because of Daylight Saving Time.

Use it online!

Check it out at unitedincome.github.io/local-crontab

Use as a script

$ npx local-crontab -h
usage: local-crontab [-h] [-v] [--tz TZ] CRONTAB

Convert local crontabs to UTC crontabs

Positional arguments:
  CRONTAB        A crontab in local time

Optional arguments:
  -h, --help     Show this help message and exit.
  -v, --version  Show program's version number and exit.
  --tz TZ        The timezone to use. Defaults to system timezone
$ npx local-crontab  '0 10 * * *' --tz America/New_York
0 15 * 1-2,12 *
0 15 1-10 3 *
0 14 11-31 3 *
0 14 * 4-10 *
0 14 1-3 11 *
0 15 4-31 11 *
$ npx local-crontab  '0 10 * * *' --tz America/Denver
0 17 * 1-2,12 *
0 17 1-10 3 *
0 16 11-31 3 *
0 16 * 4-10 *
0 16 1-3 11 *
0 17 4-31 11 *

Use as a library

Install with npm i local-crontab, then:

> const {localCrontabToUtcCrontabs} = require('local-crontab');
> localCrontabToUtcCrontabs('0 10 * * *', 'America/New_York')     
[ '0 15 * 1-2,12 *',                                               
  '0 15 1-10 3 *',                                                 
  '0 14 11-31 3 *',                                                
  '0 14 * 4-10 *',                                                 
  '0 14 1-3 11 *',                                                 
  '0 15 4-31 11 *' ]