DEFINT A-Z

DECLARE FUNCTION p% (Yr AS INTEGER)
DECLARE FUNCTION LongYear% (Yr AS INTEGER)

DIM iYi, iYf, i

CLS
PRINT "This program calculates which are 53-week years in a range."
PRINT
INPUT "Initial year"; iYi
INPUT "Final year (could be the same)"; iYf
IF iYf >= iYi THEN
  FOR i = iYi TO iYf
    IF LongYear(i) THEN
      PRINT i; " ";
    END IF
  NEXT i
END IF
PRINT
PRINT
PRINT "End of program."
END

FUNCTION LongYear% (Yr AS INTEGER)
  LongYear% = (p%(Yr) = 4) OR (p%(Yr - 1) = 3)
END FUNCTION

FUNCTION p% (Yr AS INTEGER)
  p% = (Yr + INT(Yr / 4) - INT(Yr / 100) + INT(Yr / 400)) MOD 7
END FUNCTION