For one to spill one's guts is to make a babbling and unconcise statement or speech that is so diluted with bullshit/assfacts/nonsense that it resembles non-projectile vomit:- the infectious material or foreign body is dismissed along with plenty of internal material that is not wanted.
Don't spill your guts on the best man's speech like you did at the rehearsal, and don't get drunk until you've made it.
If there are 52 weeks each of seven days in one year, and a year is 365 days, then surely 365 over 52 must be equal to seven, right? Wrong. Besides there actually being 365.24 days in a year (See leap year for the reason) there are 51 weeks and four days in a year (five days in a leap year).