How can limit time

Hello Everyone
1-How can limit time to user with hotspot server
When user active in hotspot that limit time to disable automatically for example limit 1 day after time, the user (username and password) will stopped expired.
2-the same method using pppoe server, i read in profile in “session-timeout” “idle-timeout” but i don’t know what is the difference between them.
Please explain with example.
Regards

Anyone hava idea