[FEATURE] Mimic classic cron (5 fields: min, hour, dayOfMonth, monthOfYear, dayOfWeek)

[koiuo]

Is it possible to have something like ClassicCron or UnixCron expression and parser to work with the classic cron format?

It seems, that it is not possible to implement this easily (like TimeCron and DateCron, because many classes required for that are private to cron4s).

Please consider adding this feature or suggest the easiest way to achieve this using cron4s as is.