Split time range in 1 hour intervals - excel

Question

want to split a time range into 1 hour intervals
split the given time range into 1 hour intervals from cell A2 and A3, the time range will be changed a serval time and on a (Macro) click it should split the given time range into 1 hour intervals.

Answer 1

Create an Hourly Sequence
Sub CreateHourlySequence()
Dim ws As Worksheet: Set ws = ActiveSheet ' improve!
Dim dt1: dt1 = ws.Range("A2").Value
Dim dt2: dt2 = ws.Range("A3").Value
Dim dfCell As Range: Set dfCell = ws.Range("C2")
dfCell.Resize(ws.Rows.Count - dfCell.Row + 1).ClearContents
Select Case False
Case IsDate(dt1), IsDate(dt2): Exit Sub
End Select
Dim dtDiff As Long: dtDiff = DateDiff("h", dt1, dt2)
Dim dtStart As Date, dStep As Long
Select Case dtDiff
Case Is > 0: dtStart = dt1: dStep = 1
Case Is < 0: dtStart = dt2: dStep = -1
End Select
Dim rCount As Long: rCount = Abs(dtDiff) + 1
Dim Data() As Date: ReDim Data(1 To rCount, 1 To 1)
Dim d As Long, r As Long
If dStep = 0 Then
Data(1, 1) = dtStart
Else
For d = 0 To dtDiff Step dStep
r = r + 1
Data(r, 1) = DateAdd("h", d, dtStart)
Next d
End If
dfCell.Resize(rCount).Value = Data
End Sub

Answer 2

If you are ok with a non-VBA solution, then you have some options.
Option 1: SEQUENCE
For the Excel version listed here, you could use the SEQUENCE function as suggested by chris neilsen.
Example:
Let's assume that your data starts at A1 like this:
Then, in C2, you could have :
=SEQUENCE((A3-A2)/VALUE("01:00:00")+1,1,A2,VALUE("01:00:00"))
Note that VALUE("01:00:00") represents 1 hour (but you could also use TIME(1,,) as suggested by Mayukh Bhattacharya).
Option 2: Dynamic Array Formula
You have an Excel version listed here, you can use a dynamic array formula .
Example:
Making the same assumptions as option 1, for where the data is, you could use a formula like this one:
=(ROW(INDIRECT("1:"&(A3-A2)/VALUE("01:00:00")+1))-1)*VALUE("01:00:00")+A2
Explanations:
Using the INDIRECT function inside the ROW function is a neat trick to get an array with consecutive values. For instance, INDIRECT("1:9") return the array containing rows 1 to 9 and passing it to ROW will return the array as a column like this {1;2;3;4;5;6;7;8;9} (we get only one element per row).
Since we don't know in advance how many steps we will take we calculate the number of elements using (A3-A2)/VALUE("01:00:00")+1 and concatenate it to "1:" to get the range of size that we need.
When we have the sequential array, we just need to make sure it starts by zero, which is why we remove 1 to all elements of the array like this:
ROW(INDIRECT("1:"&(A3-A2)/VALUE("01:00:00")+1))-1
Finally, we multiply each element of the array by the value corresponding to 1 hour and add the starting point in A2.
Option 3: Old array formula
Same idea as option 3 but using the old array formula explained here. Basically, you'll have to use Ctrl+Shift+Enter.

Answer 3

A Simple Solution given your example (to clear cells it is your job :-)
It would be better to write to an array but as example it should be ok.
Option Explicit
Sub TimeToHour()
Dim startTime As Double, endTime As Double, i As Double, z As Double
startTime = Range("a2")
endTime = Range("a3")
Columns(3).NumberFormat = Range("a2").NumberFormat ' Column C
z = 2
For i = startTime To endTime Step 1 / 24
Cells(z, 3) = i ' write to column c starting in row 2
z = z + 1
Next
End Sub