Formula to calculate days by month between two dates for future periods only

问题

Struggling to come up with a formula that works for this (Data in A1 - E4)

StartDate   EndDate Jan Feb Mar
12/4/2018   4/20/2019   31  28  31
9/26/2018   1/30/2019   30  0   0
1/1/2019    3/31/2019   31  28  31
1/1/2015    3/31/2019   155 141 155

IN Cell C2, formula is:

=SUMPRODUCT(--(TEXT(ROW(INDIRECT($A2 & ":" & IF($B2="",TODAY(),B2))),"mmm")=C$1))

What I am trying to do is exclude past dates from the sum, for example in the 4th row, the Jan/Feb/Mar should be 31/28/31 and not count previous years.

Any ideas where I am going wrong?

回答1:

Add a chck for the year:

(YEAR(ROW(INDIRECT($A2 & ":" & IF($B2="",TODAY(),$B2))))=YEAR(TODAY()))

and just multiply them in the SUMPRODUCT:

=SUMPRODUCT((YEAR(ROW(INDIRECT($A2 & ":" & IF($B2="",TODAY(),$B2))))>=YEAR(TODAY()))*(TEXT(ROW(INDIRECT($A2 & ":" & IF($B2="",TODAY(),$B2))),"mmm")=C$1))

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One Note:

INDIRECT is Volatile and will re-calc each time Excel re-calcs. I prefer to replace them with INDEX:

=SUMPRODUCT((YEAR(ROW(INDEX($A:$A,$A2) :INDEX($A:$A, IF($B2="",TODAY(),$B2))))>=YEAR(TODAY()))*(TEXT(ROW(INDEX($A:$A,$A2) :INDEX($A:$A, IF($B2="",TODAY(),$B2))),"mmm")=C$1))

来源：https://stackoverflow.com/questions/54012017/formula-to-calculate-days-by-month-between-two-dates-for-future-periods-only