Different resource cost for different time periods?

[perswedenborg]

This is a great library that can address tons of different problems, thanks! The only capability I’m really missing is the ability for resources to have different costs for different time periods, e.g. employee “A” costs more if he/she works during a weekend or scheduling a 4 day vacation (i.e. a 4 day task) cost more if the stay is in a hotel (resource) that costs more during one or more of the days in the stay.