Add end of month support

[guycipher]

is end of month supported? I don't seem to get errors running
0 0 21 L * ? *

I definitely don't see it in the code, just curious if I'm missing something here,

thank you.

[burakkoken]

Hi, Unfourtunately this library does not support ‘L’. Maybe I can suggest you a workaround for this. By the way, it should have returned an error at least.

Even if there is a workaround, I’m gonna create an issue to support this cron syntax .

Thank you for your feedback.