Setting format for imported data from Sharepoint

Occasional Visitor

I have data being imported from SharePoint, and like a few other posts it is pulling over in text format.

In my excel sheet I am using project dates from the imported and IF formulas to provide a value however the forumals aren't recognising the dates as dates, showing values in " " when I evaluate the formula.  How do I set the text in the SharePoint data to be viewed as a date without the need to use text to columns manually each time someone opens the document which would be a huge task. 


Any help would be greatly appreciated - even if I need to create a separate excel sheet first and pull from there instead.