In most of the exclusive Contests with real Cash prizes to be won, it says "Prizes via Neteller and Skrill are issued monthly, prizes via other methods should be issued within several days".
As the contests tend to close on the last day of the month, Skrill and Netteller prizes wil be issued at some point the following month. Because they will be issued once a "month there is probably a date set for this in advance? Writing something along the lines
"Skrill and Netteller will be issued on X day or during X week "
It tmight prevent nervous people from writing angry emails screening for their money