Create Macro To Rename Worksheets In Other Folders

I have created an appointment schedule spreadsheet. Once I get the spreadsheet running smoothly, I would like to create a worksheet for every day of the year that we are open.

I have decided to have one main folder with 26 subfolders in it. In each of those 26 subfolders, there will be one workbook with 12 worksheets in it. That will be two weeks worth of appointments as we are open Mon-Sat. Of course I want to name the worksheet tabs at the bottom of the workbook according to the appropriate calendar date. Then there is also a cell at the top of each page that also has the date, the same as the date on the tab. Just wondering if there is a simple way to create a macro to rename all these worksheet tabs, or if I have to physically open up each workbook, and rename all the worksheet tabs according to the calendar date. Then once the worksheet tab is named, can you make it automatically put the same date into Cell A1?