Here's an explanation from our support and technical staff about our event-based backtesting tool, The OddsMaker: "[OddsMaker]'s not as good at displaying warning messages as it should be. If the user's inputs make no sense -- in this case making the start time after the end time -- the software will try to replace these with reasonable values. If he really wants to see what's happening he could get the debug mode turned on for his account, but that's really aimed at programmers. If he puts in reasonable values, things will work as expected." We are not looking at pre-market trades.