(defun standardize-year (y) y)

(DEFUN weekday (DAY MONTH YEAR)
  (IF (NOT (AND (FIXP YEAR) (FIXP MONTH) (FIXP DAY)))
      (ERROR "Args to TIME:DAY-OF-WEEK must be fixnums" (LIST YEAR MONTH DAY))
      (SETQ YEAR (STANDARDIZE-YEAR YEAR))
      (LET ((A (+ YEAR (// (+ MONTH -14.) 12.)))) 
    (DECLARE (FIXNUM A))
    (\ (+ (// (1- (* 13. (+ MONTH 10. (* (// (+ MONTH 10.) -13.) 12.))))
          5.)
          DAY
          76.
          (// (* 5. (- A (* (// A 100.) 100.))) 4.)
;;          (// A -2000.)
          (// A 400.)
          (* (// A -100.) 2.))
       7.))))