You get the thoughts thats fine, its how your
reacting to them thats the problem. As Biker Bill suggests when the thoughts come up about "what time is it?" don't react by opening your eyes and as jacob suggests "just let the thought drift by". If the thought doesn't drift by and buzzes around in your head thats fine fine too, just don't react to it and simply treat it as something to observe.
If you feel an emotional reaction to not reacting to this thought (maybe sense of frustration because you feel you 'need' to know the time or a sense of anger that the thought "won't go away"), just observe that too.
I find that some meditation sessions are simply 20 mins of thoughts/emotions running through my mind and I never get into a deep state. Whilst this isn't as nice as some of the more relaxing/serene meditations I have it seems to be part and parcel of meditation. If I look at it positively these "bad" sessions are simply a good oppertunity to practice observing and not buying into the thoughts/emotions that are being experienced.
Equally were all different and perhaps the suggestion Giles makes would work better for you, just experiement and see what works for you.
