In Australia there is the requirement of a Hobbs meter to be electronically activated by flying activity within the simulator (and paused when the program is paused, etc). This time is logged and must be signed off by the instructor and the name of the pilot under instruction listed as well. Of course the times are reconciled with student log books if audited. This whole process must be documented in detail in the STOM. It should be shown that it would be difficult to tamper with the operation of the Hobbs meter, and in any case flight paths are recorded for each individual session as a further cross check for auditing.