In a small bowl, mix the softened cream cheese, chopped dill, lemon juice, salt, and pepper until well combined.

Using a sharp knife or a mandoline, thinly slice the cucumber. Peel the cucumber if the skin is tough or bitter. Pat the slices dry with a paper towel to remove excess moisture.

Lay out the slices of bread on a clean surface. If desired, lightly butter each slice. Spread a generous layer of the cream cheese mixture onto each slice of bread. Arrange the cucumber slices evenly over the cream cheese on half of the bread slices. Top with the remaining slices of bread, cream cheese side down.

Using a sharp knife, carefully trim the crusts off the sandwiches for a more refined look. Cut each sandwich into quarters or smaller triangles for easy serving. Arrange them on a platter and serve immediately, or cover with a damp cloth and refrigerate until ready to serve.