Hello
Is it possible to control the time on the day and the month of triggering a rule from the dashboard (interact with the cron function of a rule) ?
Thank you
Hi
Not at all 
However...
The project I'm working on today very kindly funded the development of the "Alarm Protocol" in OpenRemote because they needed 94 totally variable timed events in a 7 day cycle.
https://github.com/openremote/Documentation/wiki/Alarm-Protocol
Richard performed a minor miracle by creating this protocol.
Unlike using rules to achieve the same results, Richard's solution includes a delay option between events in each alarm to add even more flexibility.
(Apparently putting a delay between events in a rule halts the entire engine for the duration of the delay)
Good luck 