This is a tough one. Some people might be tempted to offer a “common sense” answer, such as “Sunday”. But that might be overlooking the fact that our senses are imperfect. It could be Wednesday. I am undecided, or agnostic.
Today (Monday) is the second day of my weekend, because I worked Saturday and have Sunday and Monday off. My task for the day is to buy some new bed linen, which I will be doing as soon as I’ve finished my morning cuppa.