I think I found the cause after using 'Find Any File' to search for 'SubmitDiagInfo', and looking at the various .plist files and opening the SubmitDiagInfo.8 (buried in the Man8 folder) document with TextWrangler.
One of the SubmitDiagInfo .plist files has a large number which I'm guessing is the time in minutes between the next submission and I guess I never noticed the Console submissions previously, unless something changed to Console Preferences where it can be disabled which I think I will do, and I sure don't recall enabling it!!!
From the man file:
"Automatic reporting of diagnostic information is off by default and no information is sent
to Apple unless a user has opted-in to automatic collection of diagnostic information.
A user is offered the opportunity to opt-in for automatic collection of additional
diagnostic and usage information after the user has manually sent a crash, hang or panic report to Apple.
A user who has previously opted in can choose to later opt out of automatic reporting by deselecting
"Automatically send diagnostic and usage data to Apple." in the Console application's preferences window.
All diagnostic and usage information which is eligible for automatic reporting is visible in the Console
application under the "DIAGNOSTIC INFORMATION" heading in the application's sidebar.
(The information appears here even if a user has not yet opted-in for automatic reporting.)
For security purposes, some system diagnostic information will only be visible to admin users. ..."
I was thinking it may have been due to some sort of snooping application.