Five is a much more sensible division of days than seven (it divides more or less into 29.5 days in a lunar month and 365 days in a solar year, better than seven does, anyway, presumably, though he's still decided not to bother with the 365/7 math problem), and it also seems like a more practical timeline for meetings of the whole group of stranded or kidnapped individuals, since seven days is a long time to wait for updates in such a critical situation. Huaisang decides not to argue either point.

"So the plan for the next ... wee-ke is just gathering information?" Huaisang asks, brow furrowed in confusion because he must have missed part of the rest of the plan. Information gathering is good, since they don't know anything right now, but scattered aimless information gathering seems like it's going to involve a lot of duplicated efforts and the likelihood of missing something important.