Most Helpful Guy
There are two things to consider here. One, in today's day and age with cell phones, people rarely put enough effort to text or call when they said they would. People are very busy and such and are easily distracted. Secondly, do we wait for these kinds of people or do we just step up and call first? Relationships are a two person endeavor so you either state that it bothers you or you give him the benefit of the doubt.
Maybe he doesn't realize that such a thing is bothersome. If it is a major thing then he needs to know. It's either a slip of mind for him or his position in the relationship isn't what you think it is.
Most Helpful Girl
He’s probably just really bad about calling or texting. Some guys will say they will call or text and then forget accidentally. There is a chance that happened so if you have been dating him and seeing him regularly I would just text him and see how his day went.