二日期之間 緊接顯示年月 (14672)

D3:D5=DATEDIF(B3,C3,"M")+1+(DAY(B3)>DAY(C3))+N(D2)

F3=LOOKUP(1,0/FREQUENCY(ROW(A1),$D$3:$D$5),A$3:A$6)&""

G3=IF(F3="","",VLOOKUP(F3,A:B,2,))

H3=IF(F3="","",TEXT(EOMONTH(G3,COUNTIF(F$3:F3,F3)-1),"YYYMM"))