I just pulled the SPSite.LastContentModifiedDate property on every site in my farm and noticed that all 315 sites were updated between the time of 5/7/2013 12:01:21 AM and 5/7/2013 1:20:00 AM.
Considering this is unlikely at that hour I am looking for explanations on why that data is being updated.
I also need a more reliable property that indicates the last time something was updated by a user.'
Thanks for the help
This is because of default timer jobs in the farm is being updated frequently.
Ref:
http://technet.microsoft.com/en-us/library/ff808317(v=office.14).aspx
You can use the LastItemModifiedDate property of the Web object.