In a medium bowl, using an electric mixer, blend together the cream cheese, dill, lemon zest and lemon juice until smooth and creamy. Then, season to taste with salt and pepper.
Cut crusts off the bread (reserve for making breadcrumbs or another use). Spread a generous layer of the cream cheese mixture on each slice of bread.
Layer the cucumber slices among three of the bread slices. Add a few sprigs of fresh dill, if desired. Top with the remaining three bread slices. Slice into quarters on the diagonal and serve (Or cut sandwiches into pretty shapes, using a favorite cookie cutter.)