Net Cafe timer in C++

[shadowmatrix]

Need help on this, thanks in advance... I have just used the code in capturing the system time but i dont know how to compute it.. from the start time to the end time...e.g start time is 10:00 pm and then it ends at 10:15 pm, and the rate for the internet is Php 15.00 per hour.. I dont know how to get the rate.. :(

[Texan40]

minutes / 60 * rate ?