Three Marks of Existence in Mahayana
Most of the time in Mahayana (both Vajrayana and Zen) I hear of Four Marks of Existence: Transience, Unsatisfactoriness, Corelessness, and Nirvana. All four are subsumed under Shunyata (Emptiness) which is equated with Pratitya-Samutpada (Dependent Co-Arising).

Not sure about past, present and future. Anyone?