My wife very kindly bought me one of the new AIM lap timers for my birthday, in its basic form not a lot dearer than the TT200.
Has added features such as a countdown timer triggered by the circuit beacon so if you've got 10mins qualifying the display will show that and count it down so you know where you are, will display lap times at the same time.
You can programme in circuit names and record your laptimes within these folders.
When it comes to race time you can programme in no. of laps if you wish and it will countdown these to the finish along with lap times.
The download options with the software available are superior to the TT range too (I believe).
Having said all of that I haven't used it yet and no, before anyone gets smart, it does'nt read in days and weeks