I think it says in progress what your time is if you put your cursor over the bar. You can also see on the numbers on the left side of the bar graph how many minutes you did. ( I got this from another comment so I didn't really know at first either.) So first you have to go to the khanacademy homepage and then go to progress on the left. (Under My Account) There are four different tabs that show up under My Progress. Click the activity tab. Then BABOOM! Theres your time or a bar graph right in front of you. Sorry if this wasn't helpful in anyway!