Hello Ranjan & Jai,
since I also have some jobs that I'd love to schedule monthly, I searched for a possibility some time ago and found none.
Maybe this is something new in IDM 8.0 (where, as far as I know, there are only preset scheduling rules and you can't create custom ones, so maybe they finally put a "monthly" option in there), but in IDM 7.2 (I'm on SP 8) you only have this:
For the frequency-type the highest unit is "hour", so even there no chance to be creative, because you have the 24 hour timeframe in which is will run.
In short: I haven't found a way to go beyond "once a week" when it comes to the time gap. :/
Regards,
Steffi.
