Question

Hello Rabbi. In the passage in Menachot 43a, there is a discussion of Rabbi Yehuda’s view, that he put tzitzit on his wife’s garments and would recite a blessing over the tallit every single morning. The Talmud asks: “From the fact that he put them on, it follows that he held it to be a positive commandment not caused by time; if so, why did he recite a blessing every morning? Like Rabbi, as it was taught: regarding tefillin, every time one puts them on, one recites a blessing over them… If so, then he should do so every hour as well? Rabbi Yehuda was a modest person and did not remove his cloak for the entire day. And what is different about the morning? Because he changed from a night garment to a day garment.” Rashi there explains that he had two tasseled garments, one for day and one for night, and that he would wrap himself in the tasseled night garment in the early morning watch when he sat down to study. If so, it is difficult for me to understand why, according to his view, he recited a blessing only in the morning. After all, if tzitzit is a positive commandment not caused by time, as indeed seems clear from the fact that he put tzitzit on his wife’s garments and also on his night garment, then why did he not also recite a blessing on the night garment, since nighttime too is a time for tzitzit?
I was also bothered further on in the Talmud there regarding a night garment that is obligated according to Rabbi Shimon, because he holds that tzitzit is a positive commandment caused by time. Why is the discussion about a “night garment” and not about “night” as a time? According to this, it would come out that someone wearing a night garment during the day would be exempt. If so, where is the meaning of “time” here? And indeed, Tosafot above on 40a bring Rabbenu Tam’s opinion, who says that even though a night garment is exempt even during the day, and a day garment is exempt even at night, it is still properly called a positive commandment caused by time, because the day causes the garment to be obligated. But this needs clarification: how is it still called time-dependent?
Likewise, later in Tosafot there they bring the Jerusalem Talmud in Kiddushin: “What is a positive commandment not caused by time? For example: returning a lost item, sending away the mother bird, a parapet, and tzitzit. And Rabbi Shimon exempts women from tzitzit. Rabbi Shimon said to them: Do you not agree with me that it is a positive commandment caused by time, since a night garment is exempt? Rabbi Ila said: The reasoning of the Rabbis is that if it were a garment designated for both day and night, it would be obligated…” And here I find it difficult: if according to the Rabbis one is not obligated in a night garment by itself, then certainly even according to them tzitzit is time-dependent, since there is a time when one is not obligated. So what is Rabbi Ila answering, that the Rabbis obligate a garment designated for both day and night? Obligate it in what, and when? Meaning, if the intent is that it is obligated in tzitzit, then we would say that this is because it is a day garment, and the fact that it is also used as a night garment does not detract from the obligation created by its daytime use. And if the intent is that it is then obligated in a blessing even at night, then why do we not also recite a blessing over a tallit designated only for nighttime?
Thank you very much in advance to my teacher and rabbi for the answer