Timing is everything To be of any value, pre-show press kits generally should reach an editor by the deadline for the preshow issue. That usually means mailing the kit two months before the issue date, thus three months before the show date. For example, Moter mails press kits in April in order to meet a deadline for a June issue publicizing a July show. But, as mentioned, she'll mail even earlier to fulfill an editor's request. That general schedule doesn't apply to all shows.
Public shows run on tighter schedules than trade shows.
Patterson sends press kits to daily publications and broadcast media only two weeks out. However, she sends kits a month in advance to weekly publications and to newspapers that do special show supplements. Even if you send a comprehensive press kit before the show, there can be value in having another one in the press room. But they do want to write about the show, so they need the information. An on-site kit also can contain updated schedules or details on seminars and special events.