clock_nanosleep and NTP drift correction

Hi all!

I have two x86 PCs running with the RT_PREEMPT patch (2.6.33.x).
Both PCs run a real time application with a thread that will be executed periodically every 1ms.
For this I use a
clock_nanosleep(CLOCK_MONOTONIC, TIMER_ABSTIME, &ts, NULL);
within the application's main loop.
The value of "ts" will be incremented after every call.

Both PCs (PC-A, PC-B) are connected via Ethernet to a third PC (PC-C) that acts as NTP time server for the other PCs (PC-A and PC-B).

My question is now:
Does clock_nanosleep() consider a potential time drift that is corrected by NTP?
Or: Will there be a significant drift between both PCs (PC-A, PC-B) by using this approach?

As the application runs very long (hours or even days) I am looking for a solution that avoids 
large drifts between the two systems.
Deltas of 1 or 2 ms are acceptable, but no time differences in tens of milliseconds.

Thanks for any help or feedback on this question

Best regards

Mathias