樓主要考慮埋當月總天數和 Last/Next 總天數, 當$D$2 係Current From Date
Last From
=EDATE($D$2,-1) + IF(DAY(EOMONTH($D$2,-1)) < DAY(EOMONTH($D$2,0)), 1, 0)
Last To
=[Current From] - 1
Current To
=[Next From] - 1
Next From
=EDATE($D$2,1) + IF(DAY(EOMONTH($D$2,1)) < DAY(EOMONTH($D$2,0)), 1, 0)
Next To
=EDATE($D$2,2) + IF(DAY(EOMONTH($D$2,2)) < DAY(EOMONTH($D$2,0)), 0, -1)