How to parse a cronline/crontab/cron with Ruby
You can use the rufus-scheduler gem to parse cronline/crontab/cron with Ruby.
Gemfile:
gem 'rufus-scheduler'
Example:
require 'rufus/scheduler/cronline'
cron = Rufus::Scheduler::CronLine.new("00 00 1 * *") # 00:00 every first day of the month
#
next_time = cron.next_time(Time.current)
previous_time = cron.previous_time(Time.current)
rufus-scheduler's cronline implementation: https://github.com/jmettraux/rufus-scheduler/blob/master/lib/rufus/scheduler/cronline.rb
See tests for details and syntax: https://github.com/jmettraux/rufus-scheduler/blob/master/spec/cronline_spec.rb