Number of Simultaneous Overlapping datetime(s)

问题

I have two columns of date/time(s) and need to find out the maximum number of them that overlap at a particular time.

Use case is this: These are start and end times for phone calls and am looking to find the number of simultaneous calls.

Column A            Column B                 
8/06/15 00:17:00    8/06/15 00:19:00     
8/09/15 00:20:00    8/09/15 00:30:00     
8/09/15 00:25:00    8/09/15 00:40:00    
8/09/15 00:35:00    8/09/15 00:50:00     
8/09/15 00:45:00    8/09/15 00:55:00     
8/09/15 00:46:00    8/09/15 00:52:00     

Expected Result:

Column A            Column B             Max Simultaneous    
8/06/15 00:17:00    8/06/15 00:19:00     0
8/09/15 00:20:00    8/09/15 00:30:00     1
8/09/15 00:25:00    8/09/15 00:40:00     1
8/09/15 00:35:00    8/09/15 00:50:00     2
8/09/15 00:45:00    8/09/15 00:55:00     2
8/09/15 00:46:00    8/09/15 00:52:00     2

The formula I am trying is this:

=SUMPRODUCT((A$2:A$35006<=B2)*(B$2:B$35006>=A2))

Problem with this, is that it counts the total number that overlap, even if at any one point they do not overlap themselves - greatly increasing the desired result.

I asked the question poorly before:

https://stackoverflow.com/posts/32486571/

回答1:

I ended up making a Sub instead of a UDF. You can set the range of the phone call log in the square brackets on the second line of the routine. I've only tested it with your six rows of sample data. It will calculate the max lines and write them one column to the right of the log (column C in the example).

Public Sub MaxLines()
    Dim c&, i&, j&, k&, min_#, max_#, n&, v, w&(), vOut, r As Range
    Set r = [a2:b7]
    v = r
    With Application
        min_ = .Min(.Index(r, 0, 1))
        max_ = .Max(.Index(r, 0, 2))
    End With
    n = (max_ - min_) * 1440
    ReDim vOut(1 To UBound(v), 1 To 1)
    ReDim w(1 To n + 1)
    For i = 1 To UBound(v)
        k = (v(i, 1) - min_) * 1440 + 1
        c = CLng((v(i, 2) - v(i, 1)) * 1440)
        For j = 0 To c
            w(j + k) = w(j + k) + 1
        Next
    Next
    For i = 1 To UBound(v)
        k = (v(i, 1) - min_) * 1440 + 1
        c = CLng((v(i, 2) - v(i, 1)) * 1440)
        max_ = 0
        For j = 0 To c
            If w(j + k) > max_ Then max_ = w(j + k)
        Next
        vOut(i, 1) = max_ - 1
    Next
    r.Resize(, 1).Offset(, 2) = vOut
End Sub

来源：https://stackoverflow.com/questions/32505368/number-of-simultaneous-overlapping-datetimes