Welcome to the forum! The official park hours are found here.
https://disneyworld.disney.go.com/park-calendars/month/
Lately, the pattern has been that boilerplate hours are first posted and then about 3 weeks or so out, they are extended (usually on a Friday) one week at a time. As of now, hours have been updated through 3/20, while 3/21 and beyond are still on the default.