Although a Friday murder would have provided more time to hide remains, clean up, and work on the alibi, I am firmly convinced SM Saturday afternoon was the earliest possible time. The killer could not afford to have someone attempt to reach her earlier, fail, and begin to inquire - or worse, contact authorities. Normally, people wouldn't think it out of the ordinary if she didn't respond to a late afternoon call or text till the following day. BM didn't take account of the wedding, BFF, and SM's family - they blew up the plan from the beginning, IMO.