profile for day and night for a same user

RouterOS General
1

hi, i wann to know that is it possible to have two profile for a user for example i wann a user to get 256kbps from 9am to 8pm and 1mbps
from 8pm to 9am

thanks in advance

2

Yes. Look at the second example on this page:
http://wiki.mikrotik.com/wiki/Manual:System/Scheduler