Change target to a 'Duration'. This is because duration is an untyped dimension (in that it doesn't support translation like Range does).

src/org/leumasjaffe/charsheet/model/magic/DDSpell.java

@@ -67,7 +67,8 @@ public class DDSpell {
 	@NonNull Range range;
 	Optional<Effect> effect;
 	Area area;
-	String target;
+	// TODO: Either rename Duration to something common, or refactor a copy and make duration have time-based controls
+	Duration target;
 	@NonNull Duration duration;
 	@NonNull String savingThrow; // TODO
 	boolean allowsSpellResistance;