Little Friday is the nickname for Thursday. Of course, most everyone knows Wednesday is "hump day". There are nicknames for other days of the week as well, but Wednesday and Thursday are the only ones I can recall.

A Bloomer is someone with a bright outlook on life who is optimistic in nature. Bloomer's frolic in every opportunity to be happy and try to make the most out of life. The opposite of a Bloomer is a Doomer. The term Bloomer originated specifically as a counter to the Doomer on sites especially like 4Chan.

another name for Wednesday when many choose to head to the bar after work and get some mid-week stress relief. Quite popular in Sweden.