Adobe Premiere would probably be your best bet. Although there's no one-step solution to removing the time stamp, there are a few ways to hide it. Possible solutions include cropping down the video to cut out the time stamp, blurring it out, or adding a graphic over the time stamp.
I'd recommend the folks over at the Premiere forum for more specific help: http://forums.adobe.com/community/premiere/premierepro_current?view=ov erview
Alternatively, you could use After Effects, although it's more of motion graphics program whereas Premiere is designed for editing.
Good luck!
