It’s Opening Day 2019, Earliest Opening Day In History!
Do we know the back story? Why so early this year? ...Not that anyone's complaining.
It’s only 1 day earlier than last year which was then the earliest Opening Day, prior to 2018 Opening Day was during the 1st week of April.
Here is the reason it changed in 2018:
The Major League Baseball season is getting off to its earliest ever start Thursday, excluding international games. The March 29 opening day is one day earlier than the previous record and is partly because of a new collective bargaining agreement that gives players an extra three to four days off.