Hi Christophe, clearly we want the most simple solution that is consistent across all platforms. So yes, please feel free to harmonize the time stamps in a logical manner.
Since you're looking at time on Windows please also consider this, which is a proposal of mine for keeping the VM's microsecond clock in sync with wall time in an efficient manner while providing a monotonic microsecond clock. I haven't had time to implement it and I could really do with a collaborator to help me.
http://forum.world.st/Time-millisecondClockValue-was-The-Trunk-Morphic-mt-10...
And this link shows it's a pressing issue for Windows users: https://www.google.com/search?q=%22Windows+image+has+system+time+delay+of+40...