some website say that my sevis fee should be paid atleast 3 days before the visa interview date whil

some website say that my sevis fee should be paid atleast 3 days before the visa interview date while I found some students who paid the sevis fee 12-3 hrs before their visa interview date. can anyone please clarify. actually I wanted to reschedule my appointment date from june 12 to may 29 but its may26 (saturday) today and I haven't yet paid the SEVIS fee. Can I pay it by credit card on sunday, may 27 and appear for a visa interview on may 29? #askall #asknikhil