Actually they should have pellets available 24/7
I know it is fasionable to try to convert them to 3-4-5 meals a day, but that is not how birds digestive systems work.
Their metabolism is way faster than ours (that why they poop every 10-15-20 etc. minutes/ depending on the size of the bird) so they should never be completely out of food.
(Not even at night- we have plenty birds here that love a midnight snack, to the surprise of their owners!)
You do not have to give them fruit every single day (too much sugar can harm them and be carefull with citrusfruit) but that all depends on portionsizes of course; every day fresh veggies are wonderfull!
How about just give the bird pellets all day and only offer seeds as a snack?
He/she will not starve, but as long as there are both pellets and seeds (s)he will pick out the favorites and leave the rest.
(Exactly the reason people started baking pellets: so the birds would eat a bit of everything all mashed together and not just pick the favorites.)