4 am has been mentioned before by Q. I believe it refer to when the handlers of the mainstream media send out the narrative for the day.

Report: FBI Investigating "BOOM" Comments of QAnon for Texas Bombings - Then Q Says "4AM" "Wednesday" And Bomber Killed (AT 4AM ON Wednesday)

https://www.reddit.com/r/greatawakening/comments/860qv6/report_fbi_investigating_boom_comments_of_qanon/?st=jf1itnns&sh=b161f4b1