Maximum Number of Overlapping Intervals

I don't fully understand the requirements, but try this:

Sub your_2()
Dim i As Long, n As Long, mm As Long
Dim va, vb
Dim xMin As Double, xMax As Double
mm = 100000000
va = Range("C2", Cells(Rows.Count, "C").End(xlUp)).Resize(, 2)
ReDim vb(1 To UBound(va, 1), 1 To 1)
xMin = mm
For i = 2 To UBound(va, 1) - 1
    If xMin > va(i, 1) Then xMin = va(i, 1)
    If xMax < va(i, 2) Then xMax = va(i, 2)

    If xMin >= va(i + 1, 2) And xMax <= va(i + 1, 1) Then
        'do nothing
    Else
        vb(i, 1) = 0
        xMin = mm:  xMax = 0
    End If
Next

For i = UBound(vb, 1) To 2 Step -1
    n = 0
        Do While vb(i - 1, 1) = ""
            vb(i - 1, 1) = n + 1
            n = n + 1:  i = i - 1
            If i = 1 Then Exit For
        Loop
Next
'put the result in col E
Range("E2:E500000").ClearContents
Range("E2").Resize(UBound(vb, 1), 1) = vb
End Sub

Akuini,

Not working on some cases.
This can be a little difficult to put into words, let me try explaining another way.
I have updated another sample with explanation in sheet :

Example 2 3.xlsb

Sorry, but it's too difficult for me. I hope someone else comes up with a workable solution.

Does the expected result achievable in Excel or do I need use other tool?

My last resort would be hire Excel freelancer or other tool freelancer.
Just let me know if the expected result is achievable in Excel or other tool (please suggest).

Thanks.

I gave it another shot, see if this works:
The result is in col E

Sub your_5_try()
Dim i As Long, n As Long, q As Long, j As Long
Dim va, vb
n = Range("C" & Rows.Count).End(xlUp).Row
va = Range("C2:C" & n)
vb = Range("D2:D" & n)
ReDim vc(1 To UBound(va, 1), 1 To 1)

'IF(MAX(D$1:D2)<=MIN(C$1:C2);1;"")
For i = 1 To UBound(va, 1) - 1
    q = i
    vc(i, 1) = 0
    Do
        q = q + 1
        If q > UBound(va, 1) Then Exit Do
        If to_Max(vb, i, q) <= to_Min(va, i, q) Then
            vc(i, 1) = vc(i, 1) + 1
        Else
            Exit Do
        End If
    Loop
Next

'put the result:
Range("E2").Resize(UBound(vc, 1), 1) = vc

End Sub

Function to_Max(vx As Variant, a As Long, b As Long) As Double
Dim h As Double, i As Long
h = vx(a, 1)
For i = a + 1 To b
    If h < vx(i, 1) Then h = vx(i, 1)
Next
to_Max = h
End Function

Function to_Min(vx As Variant, a As Long, b As Long) As Double
Dim h As Double, i As Long
h = vx(a, 1)
For i = a + 1 To b
    If h > vx(i, 1) Then h = vx(i, 1)
Next
to_Min = h
End Function

@your
Have you tried the code in post #10?

My last request is start the count from last row to top.

Try this:

Sub your_5_reverse()
Dim i As Long, n As Long, q As Long, j As Long
Dim va, vb
n = Range("C" & Rows.Count).End(xlUp).Row
va = Range("C2:C" & n)
vb = Range("D2:D" & n)
ReDim vc(1 To UBound(va, 1), 1 To 1)

'IF(MAX(D$1:D2)<=MIN(C$1:C2);1;"")
For i = UBound(va, 1) To 2 Step -1
    q = i
    vc(i, 1) = 0
    Do
        q = q - 1
        If q = 0 Then Exit Do
        If to_Max(vb, q, i) <= to_Min(va, q, i) Then
            vc(i, 1) = vc(i, 1) + 1
        Else
            Exit Do
        End If
    Loop
Next

'put the result:
Range("E2").Resize(UBound(vc, 1), 1) = vc

End Sub

@Akuini, thanks again for the second code, I really appreciate your effort help me.

You're welcome, glad to help & thanks for the feedback.
And thanks for the Rep+