GRUF (grammar rule upfront): In both the “Chicago Manual of Style 17th ed.” and “The Associated Press Stylebook 2017,” Martin Luther King Jr. Day is not abbreviated; the Jr. is part of the holiday title; and there is no comma before Jr. The two style books come to a full agreement on Martin Luther King Jr. Day!
MLK Day Is Monday, Jan. 21, 2019
Martin Luther King Jr. Day is on Jan. 21 this year, but don’t expect it to fall on this same date next year. This holiday is celebrated on the third Monday of January, so whatever date that happens to fall on is recognized.
MLK Day – AP Style
The AP Stylebook makes the rules for the holiday easy to find in the entry “Martin Luther King Jr. Day.” Besides giving some helpful bits of advice about when to celebrate the holiday and the actual birthday of the Civil Rights leader, the style book doesn’t give any other exceptions to writing “Martin Luther King Jr. Day.”
MLK Day – Chicago Style
In section 8.89 of the CMOS, titled Holidays, Chicago makes it clear that Martin Luther King Jr. Day is part of the list of official federal holidays and is, therefore, capitalized. There are no caveats, exceptions, or further clarifications. If you’re looking for a more specific writing circumstance involving reference to the new year, turn to your local style guide.
Is There a Comma Before Jr.?
In the case of the federal holiday Martin Luther King Jr., no. There is no comma that precedes Jr. The comma before Jr. was traditionally used in the Chicago Manual of Style 13th ed. and prior. However, since 1993 the style guide has switched to no comma before Jr.
In AP style, there is no comma before the abbreviations Jr. and Sr. Additionally, these abbreviations should be spelled out if they are not used with a person’s full name.
A Brief History of MLK Day
The Martin Luther King Jr. Day was first proposed as a day of remembrance for the Civil Rights leader just four days after he was assassinated in 1968. Before it was accepted as a federal holiday, just a few Northern states instated MLK Day from 1973 to 1975.
After endorsement from President Jimmy Carter, a tribute song from Stevie Wonder, and millions of petition signatures collected under the leadership of Coretta Scott King, Congress finally passed the King Holiday Bill in 1983. Not until 1986 would the first MLK Day be celebrated.
Acceptance hasn’t come smoothly to all 50 states though. Some, such as Arkansas, Alabama, and Mississippi, celebrate Martin Luther King Jr. Day alongside a commemoration to Confederate Gen. Robert E. Lee.
MLK Day’s Official Federal Holiday Name
The full name of the holiday, according to the U.S. Government Printing Office Style Manual, is “Birthday of Martin Luther King, Jr.” This name is puzzling for writers for a couple reasons. First, King was born on Jan. 15, 1929, which was a Tuesday. Celebrating his birthday on the third Monday of the month is a strange choice. Secondly, although the U.S. Government Printing Office Style calls for a comma before the “Jr.” this rule does not apply to AP Style or Chicago Style.