Difference between time stamps

[freewind]

Hi,

I have a live strategy that run on 5 minutes bars.
In OnBarUpdate() I print the local time stamp of the PC.
I'm connected to eSignal and the instruments is very active one(so this can not be the case where the bar is waiting for the first tick of the next bar to close).
The different can be from few seconds to up to ~40sec.
I regularly restart my PC and synchronizing the PC clocks.

Do you know why this drift in time happens?

Thank in advance,
Roy

[NinjaTrader_Bertrand]

What time server are you synching to here? I would expect a difference since eSignal is natively stamped data, but what you see is a bit wide.

[freewind]

I sync. to windows.com.
As I mention before I see a drift between synchronization so I don't think is the issue of the sync. server, don't you think?