Most birds will not overeat, in fact I have never heard of it. However, a bird should be fed each day if possible. A lot of hulls collect in the food dish and should be gently blown or brushed from the food and fresh food given. Even more important than the food is the water. Birds will defecate, bath etc in their drinking water, so this should be rinsed and fresh water given daily.
Every day fresh food, and clean water.
A budgie won`t overeat, so if you have a dish or something- just refill it when its empty. We have a budgie, and it eats whenever its hungry and we refill its dish about ever 3-4 days (I guess it depends on the size of you dish or feeder).
You can't put them on a schedule, you have to keep their food in the dish full all the time, they can't be without food for long at all. Hope this helps.
Everyday I guess,,, :)