To kill a mockingbird? (how long will it take for me to read?)?

So I have to read "to kill a mockingbird" for a summer assignment and I want to finish it around 2 weeks or so before September so it will be still in my mind for the test we are going to have around the first day of school. How long do you think it will take me to read this book? I know it all depends on how much time you spend reading and how fast you are, but can you give an estimate? I am a average reader I suppose, or you could just tell me how long it took you/how long you spent? I can spend any amount of minutes/hours a day as long as I can get it done by then. I haven't even seen the book yet so I don't even know how big/long it is so, sorry I'm not much a help here. Thanks for your help in advance! :)