Should we log people out after x amount of time?

The _"industry standard"_ is to have a 'Remember me' style tick box at login and allow people the option of being logged out or staying logged in.

For example:

Given we are creating a time logging app, **do we feel it is necessary to provide this option to people?**
**Should we log people out after _x_ amount of time?**

Two concerns might be: legal (_I don't have any insight here if anyone can shed some insight?_) and familiarity/perception of privacy/safety.