I just got a sefer (in Hebrew) called "Mivaer HaShabbos" by Rabbi Chaim Eliyah Rappaport, who is connected somehow to the Nanash sect of Chassidus. The book deals with the halachos (Jewish Laws) and minhagim (traditional practices) of Shabbos Koidesh. The first volume deals with the day of Erev Shabbos and preparation for Shabbos itself and the 2nd volume deals with Friday night up to the seudah. There will be more volumes in the future IY"H.
So I recently started wearing a spodik (one of those furry hats that Chassidim wear on Shabbos, holidays and special occasions, such as a bris or wedding of a famliy member). It is also called a "tall streimel". Anyway, being connected to a Polish Chassidic sect, I wear a spodik instead of a streimel, for that is the practice of Polish Chassidim.
In the first volume of the book, there is a whole section regarding the different reasons and importance of Shabbos clothing. Note 28 through 36 discuss the custom of wearing a streimel, or in my case, a spodik, on Shabbos. Some of the various reasons include: it is similar to a king's crown, it was originally a punishment for us, so we turned it into an honor to take the power out of those who would oppress us and so on. What I found really interesting is that in note 33, the author writes (my translation, so any mistakes are mine, not the author's): "There are those who have the custom of not taking their streimel/spodik off of their head for the entire night and day of Shabbos Koidesh (roughly sundown Friday night through after sundown Saturday night)". Immediately I asked myself the question that maybe you are asking at this point as well - So what do you do when you go to sleep? Is their a "shluffin' streimel/spodik" like the "shluffin koppel" (a yarmulke that religious Jews wear while we sleep)?
So I looked in the notes at the bottom of the page and sure enough, in a sefer from the Zidichov Chassidic Dynasty, a story is brought down that two of the Zidichover Rebbes, R'Tzvi and R' Itzik, had a special shtreimel to sleep in on Friday night, that was different from the one that they prayed in, so that they would never take their minds off of the importance of wearing this particular holy piece of clothing.
I am not that holy, nor can I afford another spodik, as they are very expensive, but I do find it to be a strong indicator of the importance of wearing a streimel/spodik on Shabbos Koidesh, for those who are so inclined.
I will, bli neder, write more on this topic later, IY"H, but This information was so interesting that I had to write about it now.