How we spend our days is, of course, how we spend our lives. What we do with this hour, and that one, is what we are doing. A schedule defends from chaos and whim. It is a net for catching days. It is a scaffolding on which a worker can stand and labor with both hands at sections of time...it is a peace and a haven set into the wreck of time; it is a lifeboat on which you find yourself, decades later, still living.
This is the wisdom of the monastic notion of "a rule of life." A rule of life involves a spiritual ordering and structuring of our days, mainly around times of prayer and Scripture reading, that builds intentionality into our lives. This daily intentionality is crucial for spiritual formation.
As Dillard says, how we spend our days will be, in the end, how we spend our lives. Intentionality, practiced through a rule of life, defends from chaos and whim, creating a net that catches our days and a lifeboat on which we find ourselves, decades later, still living.
If you're wondering about what a rule of life might look like, beyond fixed hour prayer practices, you might check out The Common Rule or Crafting a Rule of Life.