Time Simulator is a temporal virtualization tool transparent to you application, database and overall testing environment. It is a standard, out-of-the shelf software package: without any specific training or code modification, you can install and operate it within minutes.
Principle of Time Simulator: the tool runs at the kernel level, on a Windows server. 1. when an application makes a call to the system clock for a date/time; 2. Time Simulator intercepts the API call; and 3- returns a virtual time instead.