depends on what I am practicing.
If I am going over songs, I typically only practice them every other day, and I will go about 45 minutes in the session.
If I am learning a song, I could go for a few hours depending on the progress I am making.
But on average, during the week I get about 40 minutes a day. More time on weekends ( maybe a 2 hours on saturday and sunday).
Jlewis