node-cron's month does not follow normal cron spec

[mogzol]

node-cron's month is 0-based, while cron months are regularly 1-based. See the cron manpage: http://man7.org/linux/man-pages/man5/crontab.5.html:

field          allowed values
-----          --------------
minute         0-59
hour           0-23
day of month   1-31
month          1-12 (or names, see below)
day of week    0-7 (0 or 7 is Sunday, or use names)

So specifying a month of 4 should be April, but with node-cron, it is May: https://stackblitz.com/edit/js-7fmtr2

I don't see why node-cron would use 0-based values for the month. It is confusing for users used to other cron tools, especially when the readme recommends tools such as crontab.guru, which will tell users the wrong month: https://crontab.guru/#0_0_1_4_*

The only place in the readme that mentions this is the section that outlines cron ranges, and it fails to point out that this deviates from normal cron behaviour. It should be made more clear that node-cron's months are non-standard, or node-cron should be updated to match regular cron behaviour (though that would cause a BC break).

[jftanner]

I just discovered this as well when a job failed to run on the day expected.

This should definitely be clearly called out in the docs, since we used Crontab as linked from the documentation to verify our settings.

[intcreator]

this is correct but changing this behavior would be a breaking change so it would have to wait for 3.0 if implemented. feel free to make an MR

[sheerlox]

This is being worked on in #667 and will get released under v3 🎉

[ncb000gt]

🎉 This issue has been resolved in version 3.0.0-beta.1 🎉

The release is available on:

• npm package (@beta dist-tag)
• GitHub release

Your semantic-release bot 📦🚀