在Excel中查找以前的日期

Question

Looking for way to find out the last time an event occurred. Here is what I have for data in excel. I would like to be able to look up the Home column name in both the Home and away column then Subtract the date from the last time that name occurred. Is this possible? If so what formula am I looking for?

Date       Home Away
10/4/2017   TOR WPG
10/4/2017   STL PIT
10/4/2017   CGY EDM
10/4/2017   PHI SJS
10/5/2017   NSH BOS
10/5/2017   MTL BUF
10/5/2017   COL NYR
10/5/2017   WSH OTT
10/5/2017   MIN DET
10/5/2017   PIT CHI
10/5/2017   ARI ANA
10/5/2017   PHI LAK
10/6/2017   NYI CBJ
10/6/2017   FLA TBL
10/6/2017   VGK DAL
10/7/2017   NYR TOR
10/7/2017   DET OTT
10/7/2017   TBL FLA
10/7/2017   COL NJD
10/7/2017   BUF NYI
10/7/2017   NSH PIT
10/7/2017   MTL WSH
10/7/2017   MIN CAR

Desired outcome:

Date    |  Home|Away|Home_last|Away_Last
10/4/2017   TOR WPG 0   0
10/4/2017   STL PIT 0   0
10/4/2017   CGY EDM 0   0
10/4/2017   PHI SJS 0   0
10/5/2017   NSH BOS 0   0
10/5/2017   MTL BUF 0   0
10/5/2017   COL NYR 0   0
10/5/2017   WSH OTT 0   0
10/5/2017   MIN DET 0   0
10/5/2017   PIT CHI 1   0
10/5/2017   ARI ANA 0   0
10/5/2017   PHI LAK 1   0
10/6/2017   NYI CBJ 0   0
10/6/2017   FLA TBL 0   0
10/6/2017   VGK DAL 0   0
10/7/2017   NYR TOR 2   3
10/7/2017   DET OTT 2   2
10/7/2017   TBL FLA 1   1
10/7/2017   COL NJD 2   0
10/7/2017   BUF NYI 2   1
10/7/2017   NSH PIT 2   2

Answer 1

D2=IFERROR(DAYS($A2,INDIRECT("A"&MAX(IF(B2=$B$1:$C1,ROW($B$1:$C1),0)))),0)

1. We are going to check B2 and looking backward to see if there is a match. If so, we need it's Row number, by using ROW() , otherwise it should be 0 . However, an ordinary formula can only check one cell at a time, so we need it to be an Array Formlua . That is, it can scan through the given area one by one at a time.

2. So we have a bunch of row numbers now. We use formula MAX() to pick the biggest one, since the data are sorted by date already.

3. Now we have the Row number of the wanted date, and we know that the date is always in Column A . An Indirect() formula can easily put them together and get the date written in that cell.

4. DAYS() is designed for subtracting two dates. First argument is the date where the formula is, and second argument is the date we found by step 1 to 4.

5. However there could be some entries that no date can be found. So we put an IFERROR() outside our formula for preventing any error codes.

6. Remember this is an Array Formula , so press Ctrl + Shift + Enter to complete the formula. And you should see a {} outside you formula if you have succeeded entering it correctly.

7. Lastly, fill this formula in your chart and maybe some adjustments if unlucky.