Yes, I get those days, too. I usually spend at least a 1/2 hour each day dedicated to reading my Bible, and some time before and after dedicated for prayer. But each day is different. Some days I spend more time in His Word. Other days I do not want to read it at all.
But I try hard to read something from His Word. If I feel lazy or unmotivated, I will do like others have mentioned. I will be honest with God. I tell Him I am tired or not motivated to read His Word or whatever it is. But I stick to it. Read SOMETHING from the Bible. We should not feel obligated to read our Bibles for X amount of time each day. It should be something we look forward to. Don't force yourself. If I don't want to read much, I'll do like Esther Hadassah and read from the Psalms.
What is important is that we seek God every day! Look at Psalm 1: 1-2. It says:
Just spend even a little bit of time with God. Remember, in everything we do, we are to do it for His glory. And sometimes that means doing something we don't feel like doing.
-Sean