The first step of the smart sequence will be executed on the current day if the scheduled time has not passed the created time. For eg. If the sequence is created at 2 PM today, and the scheduled time is 4 PM, then the first step will get executed today, as the scheduled time has not passed yet.
However, if the sequence was scheduled to run at 4 PM every 3 days, and the time of setting up of the schedule is 6 PM, then the sequence will be executed only after 3 days.