1. AKA SIN. Usually a Sunday or Monday night where Bars will give drink specials to those who work in the "Service Industry," and by service industry they only mean other Bartenders, Barbacks, Waiters, Waitresses. Customer Service reps, and McDonalds drive thru workers are not considered part of this crowds service industry. SIN only occurs in areas with high concentration of Hipsters.
2.A night in which the weekend bar tender critiques and comments on the drink pouring of the day time or Sunday/Monday bartender.
When you get done from taking customer complaints at your job with Direct TV make sure to stop by Service Industry Night at the bar... O wait somehow I forgot that only bartenders get discount at service industry night.