With the Red Sox and Blue Jays both winning today, all five teams in both the AL East and NL East are now above .500. It is the first time this has happened since June 23, 1995, when the NL West and AL West both had all of their four teams above .500 simultaneously.

This Day In Baseball

On May 29, 2012 — With the Red Sox and Blue Jays both winning today, all five teams in both the AL East and NL East are now above .500. It is the first time this has happened since June 23, 1995, when the NL West and AL West both had all of their four teams above .500 simultaneously.

Source:
Baseball Reference May 29