There is nothing writing to the Apache error log and I can not find any scheduled tasks that may be causing a problem. The restart occurs around the same time, 3 times over the past week at 12:06 am. Then also in the 3-4 am time frame.
I am running Apache version 2.2.9 on Windows 2003 server version.
The same behavior was happening prior to the past week, where there was an error being written to the Apache error log indicating that the MaxRequestsPerChild limit was being reached. I found this article,
suggesting setting MaxRequestsPerChild to 0, which I did and the error stopped reporting to the error log, but the behavior of restarting continued, although not as frequently.