Actually it is not very accurate.

After the reset, it starts counting the days again (although incorrect), however 2-3 days later, it looses even those incorrect dates and jumps back to some other date in the past then begin counting again, then 2-3 days later again it jumps back to another day in the past.
If I don't sync my reader for a month, then all my bookmarks are scrambled!!!

trying to find what I left when is impossible to tell!!!!