谷歌表格； 在行号为 > 另一个公式中生成的行号的列中查找第一个包含 0 的单元格

Question

I'm making a document in Google sheets that produces the start and end times where a number of people are in a section. I was able to produce a grid, but I can't seem to find a formula for calculating end times that occur after the start time.

Time	Section1	Section2
9:00am	1	0
9:30am	1	0
10:00am	1	1
10:30am	0	1

I want to make a series of formulas that list the start and end times when people are present in a section.

1. (Start time) Find the first cell to not contain 0 and return the value in column A {I have found a formula for this step}
2. (End time) Find the first cell to contain 0 where the row number is greater than the row number of the previous start time and return the value in column A

For the first part, I can find the start time with the formula

=IFNA(INDEX($A$2:$A,(MATCH(TRUE,INDEX($B$2:$B>0,0),0))))

But when I try to adapt it to the end time by changing the greater than (>) to equals (=), it gives me the first time there is a zero regardless of if it occurs before the start time. I feel like adding some kind of row check will be necessary to fix this, but I'm not sure how. I would really rather not learn Google API if at all possible,

Answer 1

If it's just to find the first 0 after a 1, you could benefit from the use of INDEX and MATCH to create a range that goes from the first 1 to the last row and look the 0 in that range. That is: INDEX(B2:B,MATCH(1,B2:B,0)):INDEX(B2:B,ROWS(B2:B)) So, inserted in the whole formula:

=INDEX(A2:A,MATCH(1,B2:B,0)  +  MATCH(0, INDEX(B2:B,MATCH(1,B2:B,0)):INDEX(B2:B,ROWS(B2:B)) ,0)-1)