Timing belt intervals were 60k (and actually it was 40k for the automatic), then 80k, then 100k. The belt was changed between 60k and 80k -- the 60k belt has a smooth backside, the 80k has a cross-hatched pattern on it. The 100k belt is the same as the 80k belt; the only difference was a heavier-duty tensioner pulley for the 100k kit.
I don't know exactly which belt was on a 2003, but that's some information for you to start with, and someone knowledgeable on here will probably chime in with something helpful.
Or you can use the search function and there will be some threads discussing which TB was used when. Check out Paramedic's post in this thread:
http://forums.tdiclub.com/showthread.php?t=244653
Apparently 03 was sort of a changeover year. Early cars that year had the 80k bearing.
On my 2000, the timing belt interval is on a sticker under the hood, on the radiator support near the hood latch. And the owner's manual.