How about an afternoon once a week in which you simply give this time to God and learn, and prayerfully go through the Bible. Or maybe you want to pray with God as you take a walk in a park, and that can be a prayer walk. If you miss a day, God isn't going to zap you. That isn't how God works. Just don't turn it into a system, a legalism.
Prayer is a living relationship.
And so the idea of one hour a day is just a way of saying, you know, get acquainted. You spend time with your spouse because you love your spouse, because you want to be with your husband or wife, and that's the same way with God. We spend time because that is part of the love relationship. We must never be discouraged by our lack of prayer. Even in our prayerlessness we can hunger for God.