They both mean the same thing: the date /time on the system is incorrect. However you'll only get one or the other depending on the function being called (see the possibly return codes listed in the comment above each function).
Duplicate error code
In TurboActivate.h both TA_E_TRIAL_EEXP and TA_E_EXPIRED error message ID have the same number ((HRESULT)0x0000000DL) assigned but different message texts. Which text is the correct one? Or does it depend on the call that returns the error code?