Does OnTime slow macro down?
 

I am using Chip Pearson's OnTime example to run 6 Excel
reports separated by an hour each. It appears that once
the StartTimer is ran it slows the macros down
considerably. I don't want to stop the timer because I
want these macros to run every day to automatically update
my reports on a daily basis. I have a couple of questions.

1) Can anyone confirm that having 6 Excel files open with
all of them using the OnTime event procedure to run the
macros at a given time does in fact slow down the runtime
of the macros themselves?

2) If the answer to 1 is yes, can I create a 'master'
procedure that would allow me to start and stop the timer
for all 6 files?

Below is a copy/paste of the code.

Sub StartTimer()
RunWhen = TimeValue("5:00 AM")
Application.OnTime earliesttime:=RunWhe, _
procedu=cRunWhat, schedule:=True
End Sub