Blue monday

So, people usually talk about Blue Monday. Have you asked the question from yourself, why not talk about also some other days what might be same blue as Monday can be. Like fx, Tuesday, Wednesday, Thursday and so on and on. Totally we have 7 days at 1 week. Why we always talking only on Monday. Is it because that Monday comes after Sunday and Sunday is the last day of the weekend and Monday is first day of a new week.
For me, I have had blue Tuesday. In my own opinion I believe it has been same blue as some people has their blue Monday. I believe or maybe more right would be to say, I think that blue Monday can be taken bit as same as Murphy's Law: "If everything can go wrong, it will". Who also says that the Blue day has to be exact that one certain day and not through 2 days. Like from Monday evening to Tuesday evening. That is how I feel. Started yesterday and it ended today afternoon. Blue Monday does not have to always mean bad. It might be also fun:D I know, since I have had fun at least this time in my Blue day:D At least I know, that if you boil eggs bit more than a hour and you hear in kitchen how something explode and you remember that eggs was boiling, when result to see the eggs is fun:) Yellow is still yellow, but white is gray and black. But it is just one example of my Blue day :) At least I have had fun and that is important. Hope that you have also sometimes fun Blue Monday's or Blue days, not only bad ones.