on hell or harder its only reduced by a couple days like 4 or 5 days (its a 47 day birth by default on hell,93 days on doom)so the sb 10 doesn't shorten it very much on higher difficulties SB10 is also awful on hell or harder if you have it its best to just keep it around 5 or you will spew milk everywhere non stop every time you reach a red milk level of 0