We can set up timeout settings in Dynamics 365 CE. By default, the session timeout setting is set to 1,440 minutes (24 hours), which means if you have a Dynamics 365 CE browser session open for 24 hours, it will ask you to re-enter your Dynamics 365 CE credentials. We can keep the default settings or we can use our custom settings, as shown in the following screenshot: 

We also have the option to show a warning before the session expires. Apart from timeout settings, we can also set up a timeout for inactive sessions. For example, if a user has left the Dynamics 354 CE browser session inactive, we can set it to time out after a certain amount of minutes. Similarly, we can set up the timing of the warning message as well.