It really depends on how often you are hungry. If you need to drink a juice every other hour, that is ok. If you drink a juice and you don't feel hungry for 3-4 hours that is ok too. It is also best to alternate the green juices with the other blends, because the protein from the leafy green vegetables will sustain you throughout the day.
If you are finding that the juices are not going to hold you through the day try including fresh raw fruits and/or vegetables and drinking more water. Smoothies are also a great addition to juice cleanses. Bananas are a great with any combination of fruit, berries, water, and ice.