About the real time spent on a ticket

[RaphaelPinheiro]

Hello everyone!!

I've been searching for something to count the real time spent on a ticket. I'm here because those searches were unsuccessfully... I wish some counter that could be stopped and restarted over and over by the owner of the ticket.

Besides, is there any known way to do a best calculation of the cost of the service?

I appreciate any help you guys could give me!
My english is not the best, so I can try another explanation if you couldn't understand what I'm asking.