Sure, we'd all like to learn an entire language in one sitting.
  That's more a wishful thinking than having any chance at reality, though.
  In truth, language learning works best when you break your study time into small chunks, allowing the mind enough space to process the new information.
How small is small?  Let's just say it's small enough to go through just one chapter of your language learning program and do the recommended exercises.
  Sure, it may be the weekend and you have the entire day to go through five or six chapters.
  Do note that it's the equivalent of cramming, though - an activity that might fool you into thinking you know the subject, yet leaving your chance at retention as very small.
Many researches have been done into study patterns, with an overwhelming majority of them pointing towards the benefits of "chunking" your studies into small bits.
  Simply put, frequent studies over shorter periods tend to produce better results than extended sessions at infrequent times.
So how do you schedule your language lessons?  My advise is to find a short time of the day that you can do it regularly.
  Say, fifteen minutes every morning before breakfast.
  Study what you can during that period, then return back the next day at the same time, continuing from where you left off.
  Even if it feels counterproductive cutting off study time, a regular, frequent schedule will help both absorption and retention, as well as turn the sessions into a habit.