On our modded streaming server, we have changed most of the settings from default to customize the Improved Hordes mod, including reducing the minimum hours between hordes to be 4, and the minimum and maximum number of hordes per week to be much higher to try to get 3 to 4 hordes per day. On the Day 1 Vanilla game though, I added a fresh download of the mod and left all the settings at default, and the "Next Occurrence 2" problem, where it skips the first scheduled horde, was in that Vanilla game too. It doesn't appear to skip other hordes in the schedule, except for the very rare occasion where it stops spawning them altogether, and we have to restart the game to fix it (that is probably a 7D2D problem; not your mod). Hope that helps!