What does the outfit have something to do with Friday?
The theme of "nautical" doesn't have anything to do with Friday. The reason he says "it's not even Friday" here is because often times people dress fun on Fridays. In the workplace, it is common to have a "casual Friday", where employees can dress in more casual attire. Some schools participate in this as well. So Friday is known as a day where you can dress fun or different from usual. Ex: Today is Aloha Friday - everyone is wearing Hawaiian shirts.
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