The Billboard Hot 100 is the American music industry standard record chart for singles, published weekly by Billboard magazine. Chart rankings are based on radio play, streaming online, and sales; a new chart is compiled and officially released to the public by Billboard on Thursday. Example: 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 December 20, 2014, the Hot 100 has had 1,040 different number-one hits. Its current number one is "Blank Space" by Taylor Swift.