Are you talking about TD1 or TD2? This is the TD1 forum (the TD2 forum is here if that is where you meant: https://forums.ubisoft.com/forumdisp...ral-Discussion)
If you are talking about TD1, the regular vendors reset on Friday. It is at 7pm CDT. Or, if you'd rather, there is an automated timer that you can look at that shows them all: https://division.zone/reset-timers/