OK, let's find out which line of code it doesn't like.
Place a breakpoint on the first line of code in that procedure (specifically, this line):
VBA Code:
If Day(Date) <>26 Then Exit Sub
If you are not sure how to do this, then see this:
This Excel tutorial explains how to set a breakpoint in the VBA debugging environment in Excel 2013 (with screenshots and step-by-step instructions).
www.techonthenet.com
Then, save and close the Workbook.
Now, open the workbook so that the code runs.
It should stop at the line with the breakpoint.
Once it does that, click on the F8 key repeatedly, to run your code one line at a time, keeping an eye which line of code you are on.
Note the line of code you are on when this error occurs.
This is the line of code we need to focus on.