Is there any way of interpolating custom parameters into a message? From what I've read in the specification parameters are resolved against the resource bundle and attributes of the constraint annotation until there is nothing more to resolve but is there any way of adding other parameters?

Say I have an order which has an delivery date and then I'd like to validate that so the customer can request a delivery no sooner than 3 (or whatever) days from the order. I can validate that but if I'd like to spell out the minimum date in the message I can't do something like "You can request delivery no sooner than {now_plus_something}", because the "now_plus_something" doesn't resolve to anything.

It would be nice to have some sort of additional context/map which would also be consulted by the message interpolator. Currently there are no other options than a custom message resolver(?)