Moving data (with duplicates) from one spreadsheet to another - excel

Question

Background: I'm relatively new to VBA, but I see the value in becoming more comfortable using the skillset.
Goal: Move unorganized data (srce) from one spreadsheet into a different more structured spreadsheet (dest) that can later be uploaded into a software application. I have ~500 of these spreadsheets that need to be migrated, so there is an immense amount of time that could be saved by automating this.
Data: The data is a history of truck maintenance. Periodic maintenance takes place throughout the year with multiple services often performed during a single maintenance routine. Under each routine maintenance, there is a date, # of hours on the vehicle when maintenance is performed, and the type of service performed (consistently column "A").
Data Structure: All service types are contained in column A. Starting in column C & D, I have all of the dates the services performed in 2021 from C11:C34. The # of hours the vehicle has operated at the time of maintenance are contained in cells D11:D34. Subsequently, the dates and # of hours for each maintenance in 2022 are contained in columns E and F.
Challenge: While moving down the rows and before switching to the next column, I need to:
Check for repeat dates
Copy the type of services performed at that date
Paste all of those services performed under a single line item in my destination spreadsheet starting in column T and ending in Column Y (In case ~8 services are performed under a single maintenance routine.)
Question:
How can I complete the above challenge without duplicating entries and keep all services performed on the same date within a single line in my dest spreadsheet?
Below is my code thus far (I've left a comment in the section that is where I intended to craft an answer to my dilemma):
Sub VehicleDataExport()
Application.ScreenUpdating = False
'Set reference cell for output called "dest"
Set dest = Sheets("Dest").Range("A2")
'Initialize counter for destination for how many rows down we are so far
dindx = 0
'Set reference cell for source data called "srce"
Set srce = Sheets("Srce").Range("C11")
'Set reference cell for source for how many columns over we are
cindx = 0
'Set the service type index
Set serviceindex = Sheets("Srce").Range("A11")
'Collect name, vin, and in-service date
vehicle_name = Sheets("Srce").Range("A1")
vehicle_vin = Sheets("Srce").Range("B7")
started_at = Sheets("Srce").Range("B8")
'Go over from anchor column while not empty
While srce.Offset(-1, cindx) <> ""
'set row index so that it can restart everytime you switch columns
rindx = 0
'Cycle down through rows until an "DATE" is found
While srce.Offset(rindx, cindx) <> "DATE"
'Set counter for duplicate index so the program will move through the data while looking for duplicate DATES
duplicateindx = 0
'If statement to determine if something is in the cell - 2nd header row
If srce.Offset(rindx, cindx) > 0 Then
'True Case: copy the date, hours, and service type
service_date = srce.Offset(rindx, cindx)
service_hours = srce.Offset(rindx, cindx + 1)
service_type = serviceindex.Offset(rindx, 0)
meter_void = ""
'Properly label and account for Dot Inspection
If service_type = "DOT Inspection" Then
service_hours = 0
meter_void = True
'secondary_meter_value needs to be 0
'secondary_meter_void needs true
End If
'CHECK FOR DUPLICATE DATES AND COPY THEM TO A SINGLE ROW IN THE DESTINATION
'Paste all of the numbers into a destination row
dest.Offset(dindx, 0) = vehicle_name
dest.Offset(dindx, 1) = vehicle_vin
dest.Offset(dindx, 2) = started_at
'Variable inputs
dest.Offset(dindx, 3) = service_date
dest.Offset(dindx, 13) = service_hours
dest.Offset(dindx, 17) = service_type
dest.Offset(dindx, 14) = meter_void
'Add to both the row and destination indexes
rindx = rindx + 1
dindx = dindx + 1
'If no inspection is found, move down one row
Else: rindx = rindx + 1
'End if statement
End If
'end column specific while loop
Wend
'add two to the column index - account for both the date and hours column
cindx = cindx + 2
'End the initial while loop
Wend
Application.ScreenUpdating = True
End Sub

Answer 1

This really sounds like a job for PowerQuery but if I was to tackle it with VBA I'd use a Scripting.Dictionary. I would also write a small data class that includes all of your service types as Boolean.
I don't fully understand your data structure but some pseudo code might look like this:
Const SRVCECOL As Long = 1
Const HOURSCOL As Long = 2
Function ExtractTransformServiceData(src As Workbook) As Object
Dim dict As Object
Set dict = CreateObject("Scripting.Dictionary")
Dim svcDates As Range
Set svcDates = src.Sheets(1).Range("C11:C34")
Dim svcDate As Range
For Each svcDate in svcDates
Dim tsd As TruckServiceData
If dict.Exists(svcDate.Value) Then
Set tsd = dict.Item(svcDate.Value)
Else
Set tsd = New TruckServiceData
dict.Add svcDate.Value, tsd
End If
tsd.SetHoursForService( _
svcDate.Offset(0, SRVCECOL).Value, _
svcDate.Offset(0, HOURSCOL).Value)
Next svcDate
Set ExtractTransformServiceData = dict
End Sub