[rules-users] Working with dates in rules

Hi- I'm wondering how it would be possible to compare a part of a date in the lhs condition of a rule in a Drool. In other words, I need to compare a date to see if it is *x* days from the current date, *n* hours from current time, etc. Would anyone be kind enough to provide an example? I'm thinking I may have to implement something of my own to offer that functionality? Big thanks, David