Friday brew day. Water is prepped, 750ml starter of spooky saison ready to pitch. Mash started around 7am.
Based on boiling 20.00 gallonsliters at 1.029 for 75 minutes, this will decrease your wort by 4.06 gallonsliters, bringing your after boil OG to 1.035. You wanted an OG of 1.042. It looks like it will be under.