AWS EventBridge cron expressions are weird

They have some specifics to them that are unexpected if you have been working with regular crontabs for some time.

That is why I made this simple tool that helps you check your cron expressions. It validates these expressions against the AWS API as well.

EventBridge cron expressions are made in “Quartz” format so they differ in a couple of places:

  • Some expressions can not be made with them
  • They include the year while normal crons do not
  • Some of the indexing is different for instance days start at 0 in normal crons and in AWS EventBridge crons they start at 1

Currently the tool does not support rate() expressions.