Not necessarily. Your total dreaming time is limited by your sleep cycles and the amount of REM sleep you get. At their max, your sleep cycle will have about 80-90 minutes of REM, so technically this is the most amount of time you can possibly be lucid at a time.

However, there are techniques called Time Dilation that can make your time lucid feel longer than just 80-90 minutes, to possibly a few hours or more. I would recommend reading this thread: My Tutorial for extending Lucid Dream Time. Hours of LD. - Lucid Dreaming - Dream Views