#s(tz
   (#s(span #s(*date 2006 8 7 0 0 0 -18000) -21600 0 2006 "CST")
    #s(span #s(*date 2006 5 7 0 0 0 -21600) -21600 3600 2006 "CDT")
    #s(span #s(*date 1988 9 24 0 0 0 -18000) -21600 0 1988 "CST")
    #s(span #s(*date 1988 5 7 0 0 0 -21600) -21600 3600 1988 "CDT")
    #s(span #s(*date 1987 9 27 0 0 0 -18000) -21600 0 1987 "CST")
    #s(span #s(*date 1987 5 3 0 0 0 -21600) -21600 3600 1987 "CDT")
    #s(span #s(*date 1921 4 1 0 0 0 -20932) -21600 0 1921 "LMT")
    #s(span -inf.0 -20932 0 -inf.0 "LMT"))
   #s(*zone-span -21600 () "C~aT")
   (#s(span #s(*date 1921 4 1 0 0 0 -20932) -21600 0 1921 "LMT")
    #s(span -inf.0 -20932 0 -inf.0 "LMT")))