The format for the activity tab is hour:minute, so if you wanted to enter an hour, your can enter 1:00.
As far as calories burned, we use a standard estimation of calories burned. This is just an estimation and everyone has different values. If you want to look at other ways of estimating calories burned, you can click on the "Customize" link next to your lifestyle calories burned in the activity tab and customize your metabolism.
Let me know if this helps.