#s(tz
   (#s(span -inf.0 -25200 0 -inf.0 "MST"))
   #s(*zone-span -25200 () "MST")
   (#s(span #s(*date 2039 12 1 0 0 0 -25200) -25200 0 2039 "MST")
    #s(span -inf.0 -25200 0 -inf.0 "MST")))