The Billboard Hot 100 is a list of the current most popular music made by Billboard magazine. Rankings are based on radio play and sales; the tracking week for sales is each Monday to Sunday, while for radio play it is Wednesday to Tuesday.[1] A new chart is made and officially released to the public by Billboard on Thursday. Each chart is dated with the "week-ending" date of the Saturday two weeks after. Example:[2]
Monday, January 1 – sales tracking-week begins
Wednesday, January 3 – airplay tracking-week begins
Sunday, January 7 – sales tracking-week ends
Tuesday, January 9 – airplay tracking-week ends
Thursday, January 11 – new chart released, with issue date of Saturday, January 20.
The first number one song of the Hot 100 was "Poor Little Fool" by Ricky Nelson on August 4, 1958. As of the issue for the week ending April 9, 2023, the Hot 100 has had 1,143 different number-one hits.