Billboard's US and Canadian Hot 100 are based on a Saturday issue date that is actually about 11 to 13 days ahead of the survey period. For digital sales the period is Monday to Sunday, and for airplay it is Wednesday to Tuesday.
So the Billboard Hot 100 dated Saturday, January 24th, is based on digital sales data for the period Monday, January 5th to Sunday, January 11th, and airplay data for the period Wednesday, January 7th to Tuesday, January 13th.
Billboard posts the Hot 100 on its website for the January 24th issue on Thursday, January 16th, mails them out on the 17th and they arrive starting the 19th (I will probably get mine on Wednesday).
Hope that helps.