I really do not have a schedule of changing my smartphone. Though as far as I remember, I haven't experienced having a cellphone for almost 2 years. This is because, sometimes it gets broken easily and/or it is lost or taken from me by a thief. Buying a new smartphone is costly especially if you are looking for the latest phones. That is why, I do not change my phone easily, except if I have extra money to buy one. I feel that as long as it is being useful to me and it meets my expectations, I won't change my phone yet.