Yes, Excel can automatically insert the current date into a cell when a file is opened up. You can use the function to achieve this. Here are the steps to do it:

1. Select the cell where you want to insert the current date.
2. Type the formula
   Code:

   =TODAY()

   in the formula bar.
3. Press Enter.

Now, every time you open the file, the current date will be automatically inserted into the cell you selected. If you want to format the date in a specific way, you can use the Format Cells option. Right-click on the cell, select Format Cells, and choose the date format you prefer.

Another option is to use a macro to insert the current date. Here are the steps to create a macro:

1. Press Alt + F11 to open the Visual Basic Editor.
2. Click on Insert and select Module.
3. Type the following code:
   
   
   Formula:

   Sub Auto_Open()
Range("A1").Value = Date
End Sub 

4. Replace "A1" with the cell where you want to insert the date.
5. Save the macro and close the Visual Basic Editor.

Now, every time you open the file, the macro will run automatically and insert the current date into the cell you specified.