Data Validation on Linked Cells

Hi there!
I am looking to track outgoing calls for our call center daily automatically.

I have sheet right now that automatically updates when a call is made (a value is changed within one of my agent's excel lists and my list counts it). I would like to track the amount of calls made by each agent daily automatically within different cells. I've seen data validation used to limit data entered after a certain date, though when I try to to limit data using this feature on a linked cell, the content will still update. Is there a way to "freeze" content entered into a cell after a certain date, even if the cell is updated through a formula or while linked from a different cell?

Thanks so much for the help,

Mike.

To freeze a content/cell, please use protect sheet under "Review" tab.

If you have any doubt, please write back to us and suggest you to upload a sample sheet.

Thanks for the reply- unfortunately I do not have a sample sheet since I have been unable to produce results. However- I do have a screenshot which might help: example.PNG

To further clarify- within a sheet I have a column of linked cells all pulling from the same data point. On the left side of the column are a series of dates- these are the individual dates we would like to track connects from.
On the right side of the column are the linked cells- once again, each of these cells are pulling from the same exact data point. However- I would like the data being pulled to freeze once it has it the date on the corresponding left column.
For example: if the date on the left column is 5 July- numbers on the right column would stop updating, or freeze on July 6, beyond.

Let me know if this makes more sense!

Does anyone have a solution to this?