"Having eyes, but not seeing beauty; having ears but not hearing the music; having minds but not perceiving the truth; having hearts that are never moved and therefore never set on fire. These are the things to fear." -Tetsuko Kuroyanagi
There is no specified time that you are required to fall in love with someone. It should be natural. If you want to just play around and have a good time, then it makes sense that you won't feel love. However, if you find someone that means a lot to you, and you start to experience a lot with them, talk a lot, spend a lot of time together, if months and months go by and you just don't think it's love, then maybe it's time to move on.