Change table headers to count from a chosen starting day until the last column

[Xalova]

Okay, so i have a huge table which is roughly about 300 columns long. most of the headers are dates. What i need is that i change only the starting date of the project and the table headers automacially update accordingly.

i would do it simply with "=(cell left to the chosen cell)+1". But that doesnt work since they are table headers. I wanted to try to use VBA to solve this problem, but i wouldnt know where to begin. Maybe with a loop?

thanks in advance

 

[mart37]

Dim cll As Range
For Each cll In Range("Table1[#Headers]")
    cll = Date + cll.Column - 1
Next

 

[Xalova]

Dim cll As Range
For Each cll In Range("Table1[#Headers]")
    cll = Date + cll.Column - 1
Next

thats great, but the headers with state start in the 4th column. From there onwards, how do i change that? I tried it with Range("Table1[[#Headers];[Column2]:[Column300]]") but that didnt work.

 

[mart37]

Dim Cll As Range
Dim StartDate As Date
Dim StartCol As Integer
StartDate = DateSerial(2021, 4, 16)
StartCol = 4
For Each Cll In Range("Table1[#Headers]")
    If Cll.Column >= StartCol Then Cll = StartDate + Cll.Column - StartCol
Next