100 PROGRAM "Longyear.bas"
110 DEF RD(Y)=Y*365+INT(Y/4)-INT(Y/100)+INT(Y/400)
120 DEF LONGYEAR(Y)=(4=MOD(RD(Y),7)) OR(4=MOD((RD(Y-1)+1),7))
130 INPUT PROMPT "Start year: ":S
140 INPUT PROMPT "End year:   ":E
150 FOR Y=S TO E
160   IF LONGYEAR(Y) THEN PRINT Y,
170 NEXT
180 PRINT