#s(tz
   (#s(span #s(*date 1991 9 15 0 0 0 32400) 28800 0 1991 "CST")
    #s(span #s(*date 1991 4 14 0 0 0 28800) 28800 3600 1991 "CDT")
    #s(span #s(*date 1990 9 16 0 0 0 32400) 28800 0 1990 "CST")
    #s(span #s(*date 1990 4 15 0 0 0 28800) 28800 3600 1990 "CDT")
    #s(span #s(*date 1989 9 17 0 0 0 32400) 28800 0 1989 "CST")
    #s(span #s(*date 1989 4 16 0 0 0 28800) 28800 3600 1989 "CDT")
    #s(span #s(*date 1988 9 17 0 0 0 32400) 28800 0 1988 "CST")
    #s(span #s(*date 1988 4 16 0 0 0 28800) 28800 3600 1988 "CDT")
    #s(span #s(*date 1987 9 13 0 0 0 32400) 28800 0 1987 "CST")
    #s(span #s(*date 1987 4 12 0 0 0 28800) 28800 3600 1987 "CDT")
    #s(span #s(*date 1986 9 14 0 0 0 32400) 28800 0 1986 "CST")
    #s(span #s(*date 1986 5 4 0 0 0 28800) 28800 3600 1986 "CDT")
    #s(span #s(*date 1980 5 1 0 0 0 30600) 28800 0 1980 "CHAT")
    #s(span #s(*date 1966 5 1 0 0 0 32400) 30600 0 1966 "CHAT")
    #s(span #s(*date 1940 1 1 0 0 0 28800) 32400 0 1940 "CST")
    #s(span #s(*date 1932 3 1 0 0 0 30600) 28800 0 1932 "CHAT")
    #s(span #s(*date 1928 1 1 0 0 0 30404) 30600 0 1928 "LMT")
    #s(span -inf.0 30404 0 -inf.0 "LMT"))
   #s(*zone-span 28800 () "C~aT")
   (#s(span #s(*date 1928 1 1 0 0 0 30404) 30600 0 1928 "LMT")
    #s(span -inf.0 30404 0 -inf.0 "LMT")))