According to Bio Kids, baby robins leave the nest about 2 weeks after hatching. After leaving the nest, which is called fledging, baby robins at first stay on the ground, close to their parents. The chicks are able to sustain flight about 2 weeks after fledging.
Robin eggs incubate for approximately 14 days, with the female parent brooding on the nest in order to keep the babies warm. When the babies are old enough to stay warm, the female parent will only be on the nest when there's bad weather or at night.
When the nestlings leave the nest they do so within 1 day of one another.