Why do Orthodox Christians pray at set times morning and evening?

This is one of the fundamental reasons why we spend time every day in structured prayer, in the morning and in the evening, in order to cap our days with that preparation for the day and the preparation for sleep and the preparation to continue to press forward. Just tackling that one day at a time, not looking at our whole life, but just for today. What do I need to do and accomplish? And if there's something tomorrow, I'll write it down and plan accordingly to the best of my abilities. But I will live every day and today, not in the failures of yesterday or the unmet expectations, or in the future possibilities of what could happen in my life, but being forever right now, right here, in our prayer life with Christ.