S9 LIB  (proper-time? time-list)  ==>  boolean

        (load-from-library "proper-timep.scm")

Return #T if the given TIME-LIST is a proper TIME-LIST as defined
by the UNIX-TIME->TIME procedure. Otherwise return #F.

(proper-time? '(3 1970 1 1 0 0 0))  ==>  #t
