Pixar Fest will end Labor Day Weekend, so if you want to see the Pixar Play Parade in DL and the things associated with Pixar Fest, you'll need to visit before early September this year. There has been no official word whether PTN will remain in DCA beyond Labor Day Weekend. Lots of people hope so. Pixar Pier in DCA will open June 23rd. March can be tricky for trip planning because you have low season or Spring Break. Usually there is something like the Food & Wine Festival in DCA to pull in more locals, too. So it depends on when in March.
We can’t go this year at all. But we can really go anytime next year between feb and before Star Wars land opens.