One possible culprit is creating a lot of documents in a very short amount of time. The date/time created is not typically stored on a document in a field. Instead it is identified via the UNID (see http://www-12.lotus.com/ldd/doc/domino_notes/9.0/api90ug.nsf/85255d56004d2bfd85255b1800631684/00d000c1005800c985255e0e00726863?OpenDocument). However, since UNIDs need to be unique, create enough documents in the future, and it will increment the UNID. If you're following where that goes, it means the created date will also get incremented, into the future.

If there is a $Created item on the document, this takes precedence (see http://www-12.lotus.com/ldd/doc/domino_notes/9.0/api90ref.nsf/f961929dc6dc14dc852561bf0067d1c4/85255d56004d3f63852564da001213e9?OpenDocument), which is what you would typically do if you set the UNID (instead of letting Notes/Domino automatically calculate it) and want to keep the created date/time.

If this were just on a set of auto created documents, then I would understand.   And, no, I'm not using a $Created field anywhere.

I also noticed late yesterday that the date on the database itself is 4/15.  It's that way on the customers server, however, my local replica still shows the current date correctly.

I also noticed that the time is fishy.  Yesterday, the document for my xpage showed a save time of 5:32:38 PM (even though I did that around 3:00pm)

Just this morning at 9:20am, I saved that same document again and now it shows the save time is 5:32:45 PM.

It's not just this document, either - I tried saving another one 5 minutes after this one and got the same save date, but a time of one millisecond later, 5:32:46 PM.

Is there a fixup command that I can try that might clear this up?

So, following your example, perhaps someone did mess with the windows clock at some point.  It shows correct now.  So, why would the db and documents still get a messed up date/time?  If Notes uses the system date/time, then I would think that now that the clock is correct, then Notes would be using the correct date/time.  I'm just not understanding how all this works - but, regardless - how do I get it fixed?