Do EA decisions come out by or on December 20th

For WPI, the website says that decisions come out by the 20th, does this mean that I will get my decision any time before then? Or just on December 20th

Last year EA applicants got their decisions on the 20th.

Last year EA was on December 19 at exactly 5pm and not a minute before.

WPI just posted on Facebook - WPI Admissions BIG NEWS! We will be releasing Early Action 1 Application Decisions this coming Monday, 12/16 at 5 pm EST through the applicant portal! Keep an eye on your emails, everyone!