When does Juneteenth start being a federal holiday?

In 2020, Juneteenth was formally recognized by New York City as a yearly official city holiday and public school holiday, starting the year after. It will become the 12th federal holiday in America. Who voted against Juneteenth? Despite the overwhelming support for the bill, it wasn’t a clean sweep when being passed through Congress.

https://www.the-sun.com/news/3100011/when-does-juneteenth-start-being-a-federal-holiday/