CiviMail send immediately date/time check too sensitive

I've had several users report that when choosing to schedule a mailing to "send immediately" they occasionally receive the popup warning indicating they are scheduling the mailing in the past. I believe that code is handled client side, so it may be caused by differences in the user's computer clock. But regardless, if the user is choosing to send immediately, I don't think we should be running any date/time validation at all. That should only be relevant if they are scheduling a specific date/time.