Value of _viewts and server timestamp having huge disparities

Hello all! I’m encountering some strange behavior on my piwik install, and am wondering if anyone else has run into this.

So, I have this log entry from my nginx log:

10.114.10.254 - - [18/Dec/2012:04:58:16 +0000] “GET /phx.php?action_name=bla.com&idsite=35&rec=1&r=284588&h=21&m=44&s=3&url=http%3A%2F%2Fm.bla.com%2FSmartDeviceBATMobile%2FSmartDeviceDefault.aspx&_id=2b868a5ccb12d9bb&_idts=1297046644&_idvc=1&_idn=1&_refts=0&_viewts=1297046644&cookie=1&res=640x394&_cvar=%7B%221%22%3A%5B%22vtrack%22%2C%2230209679%22%5D%2C%222%22%3A%5B%22pid%22%2C%222724017%22%5D%2C%223%22%3A%5B%22cid%22%2C%22429866%22%5D%7D HTTP/1.1” 200 54 “http://m.bla.com/SmartDeviceBATMobile/SmartDeviceDefault.aspx” “Mozilla/5.0 (Linux; U; Android 2.3.3; en-us; MID8125 Build/GRI40) AppleWebKit/533.1 (KHTML, like Gecko) Version/4.0 Mobile Safari/533.1” “98.22.96.165”]

(I have changed the URLs to obfuscate client identity). There are two things to note here:

  1. The web server log entry says Dec 18, 2012
  2. the value of _viewts = 1297046644, which is Sun, 06 Feb 2011 21:44:04 -0500

This seems… not right, considering that the site in question was created in January 2012. Has anyone else run into this issue? I have only two guesses here:

  1. since _viewts is set in the JS tracker using javascript’s Date object, then perhaps the user’s system time is just not set right.
  2. This isn’t “real” traffic, just someone manually setting _viewts in the request

Both seem a little far fetch, but perhaps someone else has some ideas? To give an idea about volume, this happened for about ~190 visits out of about 2 million visits.