Select range based on time.

[powersp68232]

I have data like the image below. I am trying to select a range from Cell B7 to Cell B908, Do Something, Select range B909 to B1807, Do Something, and continue this loop until I get to the last row of data. The cycle runs about 45sec each time, but there are always multiple instances of the time stamp. So, I am needing to be able to select the last row with that timestamp and then create a loop to complete the same on each cycle.

Ex.

Private Sub Find_Range_Time()

Dim sTime As Range, fTime As Range, Total As Integer, LastRow As Long

'Set range with initial start time.
sTime = Range("B7")

'Find last cell with Finish Time
'This should locate the last cell that contains the finish time of the current cycle
'All cycles are 45 seconds

<code here>

'Do this loop on current cycle range
Total = (LastRow / 45) / 20
i = 1

For i = i To LastRow
Set Chart = Range("C" & sTime, "C" & fTime)

'Set sTime to cell fTime with offset of 1

sTime = fTime.Offset(1, 0)
Next i

End Sub