Topic: cron a line
It would be desirable to create a certain function, which on the basis of the given date - dt , and lines of the schedule a crone cron , for example
0 1 3/2? * WED, THU, FRI
Returns the list of dates (probably empty) in which works crones for the given date dt .
That is it is clear, what the basic complexity is not present, but an amount of small nuances big enough, whether there is no ready implementation casually (in any language)?