Anousha Sakoui and Mark Gurman, reporting for Bloomberg:

[Apple] is planning a March 25 event to announce both services, according to people familiar with the plan. The iPhone maker invited Hollywood stars, including Jennifer Aniston, Reese Witherspoon, Jennifer Garner and director JJ Abrams, to attend, one of the people said.

Earlier, John Paczkowski at Buzzfeed News first reported that Apple was planning at event on March 25, supposedly to announce its News subscription service.