Set zucchini in a colander, sprinkle with salt and drain for 1 hour. Squeeze out excess moisture from zucchini then cook it for a few minutes in olive oil. Season to taste from salt and pepper and set aside to cool slightly.
In a mixing bowl combine the eggs with the milk, feta cheese, parsley, dill, and bread crumbs. Add the cooked zucchini and adjust the seasoning, using lots of pepper.
Preheat the oven to 350 degrees. Butter a 9 by 13-inch deep baking pan. Layer a sheet of phyllo so that it overlaps baking pan and extends beyond the rim. Brush the sheet very lightly with melted butter and cover with another phyllo sheet. Continue this way until half of the phyllo has been used. Add the zucchini and spread it out evenly. Fold overhanging phyllo up over the squash filling and brush with melted butter. Lay remaining phyllo leaves on top, again brushing melted butter between the layers. Brush top well with butter, score top layers with a sharp knife and bake for an hour. Cool and serve with a green salad or a vegetable salad of green beans, tomatoes and olives.