Dear all,
I had the same problem here. There are only few answers to this on the web, but the most common one is relevant and worked in my case:
1/ start in safe mode. If the messages disappear in safe mode,
2/ restart in normal mode, move all non-system extensions (/Library/Extensions), Launchagents (/Library/LaunchAgents) and Launchdaemons (/Library/LaunchDaemons) somewhere else and restart again. If the messages do not appear,
3/ move back some of those files to their initial position, restart, check console, continue moving back etc... until you find which extension, Launchagent or Launchdaemon is responsible for the invalid timestamps
All the best,
Alexis