So here's what went down: some guy dissected Ice Cube's song "It Was a Good Day" and figured out exactly which day he was talking about. At first, it just seems like a song about any old good day, but, based on the information given by Ice Cube in the lyrics, someone was able to piece everything that went on that day as described and discern that the "good day" was January 20, 1992.

Here's the original article by Donovan Strain of LimeWedge to give you the bigger picture of what happened:

Believe it or not, there are individuals in this world that don’t just take take life at the surface, but dig deeper in search of the truth. Donovan Strain is one of these, he’s discovered Ice Cube’s Official “Good Day”.

CLUE 1:

“went to short dogs house,
they was watching Yo MTV
RAPS”
Yo MTV RAPS first aired:
Aug 6th 1988

CLUE 2:
Ice Cubes single “today was a good day” released on:
Feb 23 1993

CLUE 3:
”The Lakers beat the Super
Sonics”
Dates between Yo MTV Raps air date AUGUST 6 1988 and the release of the single FEBRUARY 23 1993 where the Lakers beat the Super Sonics:
Nov 11 1988 114-103
Nov 30 1988 110-106
Apr 4 1989 115-97
Apr 23 1989 121-117
Jan 17 1990 100-90
Feb 28 1990 112-107
Mar 25 1990 116-94
Apr 17 1990 102-101
Jan 18 1991 105-96
Mar 24 1991 113-96
Apr 21 1991 103-100
Jan 20 1992 116-110

CLUE 4:
Dates of those Laker wins over SuperSonics where it was a clear day with no Smog:
Nov 30 1988
Apr 4 1989
Jan 18 1991
Jan 20 1992

CLUE 5:
“Got a beep from Kim, and
she can fuck all night”
beepers weren’t adopted by mobile phone companies until the 1990s. Dates left where mobile beepers were availible to public:
Jan 18 1991
Jan 20 1992

CLUE 6:
Ice Cube starred in the film “Boyz in the hood” that released late Summer of 1991, but was being filmed mid-late 1990 early 1991 and Ice Cube was busy on set filming the movie Jan 18 1991 too busy to be lounging around the streets with no plans. Ladies and Gentlemen..

The ONLY day where:
Yo MTV Raps was on air
It was a clear and smogless day
Beepers were commercially sold
Lakers beat the SuperSonics
and Ice Cube had no events to attend was…

JANUARY 20 1992: National Good Day Day