sort list by date in descending order – groovy madness

Instead of

things.sort{-it.dtCreated}

you might try

things.sort{a,b-> b.dtCreated<=>a.dtCreated}

reverse() does nothing because it creates a new list instead of mutating the existing one.

things.sort{it.dtCreated}
things.reverse(true)

should work

things = things.reverse()

as well.