How does the system keep track of the number of used days in the trial version

The system calculates the difference between the first entry date and the last entry date. Entering an out of sequence dates will hasten the expiry notice to appear on the system. However, if the expiry notice does appear and you can’t access the system, it does not mean that you have lost the data you have already entered, it just means you can’t access it. Once you obtain a product key, you can resume working from the point where you last accessed the system.