Gemara

Had the Mishnah taught only that there is Me'ilah for Pasul Avodah done during the day, which is the time for Hakravah, we would not know that Me'ilah applies when Shechitah was at night, for night is Pasul for Avodah;

Had the Mishnah taught only that there is Me'ilah when Shechitah was at night, one might have thought that this is because Zerikah (the primary Avodah) was during the day, but if it was slaughtered during the day and Zerikah was at night; there is no Me'ilah.

Menachos 40b (Rava): If one put Tzitzis on the three corners of an unfinished garment, then finished the garment, the Tzitzis are invalid due to Ta'aseh v'Lo Min ha'Asuy (one must make them in a way Kosher for the Mitzvah).

Rishonim

Rambam (Hilchos Ishus 4:7): If a minor was Mekadesh, it is invalid.

Mishneh l'Melech: A Mishnah (Kidushin 50b) clearly teaches this. If he said 'you are Mekudeshes to me after I mature', what is the law? Since he was a minor at the time of Kidushin, it is invalid. Or, since he stipulated that Kidushin will take effect when he is an adult, it takes effect? We cannot learn from the Mishnah (Kidushin 62a), which discusses Davar she'Lo Ba l'Olam. I.e. he cannot be Mekadesh her until an action, i.e. conversion, freedom, or death. Here, the time comes by itself. Perhaps this is Ba l'Olam. We do not permit a vow until it takes effect. Some say that this is only if it is Mechushar Ma'aseh (it cannot take effect until an action is done), but not if it is only Mechusar Zeman, for time comes by itself. In Gitin 85a, we asked whether a Get that does not permit her to become Mekudeshes to a minor is valid. Now he cannot be Mekadesh, but later he can. Even though Pidyon ha'Ben before 30 days is invalid, one can redeem and stipulate that it take effect after 30 days, because the time comes by itself.

Poskim

Shulchan Aruch (OC 10:5): If one put Tzitzis on a three-cornered garment, then made a fourth corner and put Tzitzis on it, it is Pasul due to Ta'aseh v'Lo Min ha'Asuy.

Shulchan Aruch (14:1): A woman may attach Tzitzis.

Rema: Some are stringent to require men. It is good to be stringent l'Chatchilah.

Aruch ha'Shulchan (7): Even though women are exempt from Tzitzis, they may make Tzitzis. A Gezeras ha'Kasuv disqualifies them from writing Tefilin, but not from Tzitzis. We say that 'one who is exempt cannot be Motzi others' regarding a Mitzvah itself, such as Kidush or Havdalah. Regarding Tzitzis, the Mitzvah is wearing it. It is a mere stringency that some require men. Surely one may tie Tzitzis at night, even though there is no Mitzvah at night, for even women may tie, and they are not commanded at all.

Shulchan Aruch (18:1): The Rambam exempts anything one is wearing at night, even if the garment is normally worn during the day.

Taz (1): In any case the Rambam permits to wear a garment with Tzitzis on Shabbos night in Reshus ha'Rabim. This is not carrying, for the Tzitzis are an adornment for the garment.

Mishbetzos Zahav: If Tzitzis of a day garment snapped, may one make Tzitzis for it at night? This is not Ta'aseh v'Lo Min ha'Asuy. The Rambam exempts a day garment at night, but Mechusar Zeman does not apply to a Mitzvah that will apply later that day. This is unlike putting Tzitzis on a three cornered garment. It is not obligated in Tzitzis at all. If one put Tzitzis on a garment with Sha'atnez, and later he removed the Sha'atnez, this is Ta'aseh v'Lo Min ha'Asuy. When he attached the Tzitzis, this was not "Asher Techaseh Bah" (a garment you wear, for nowadays there is no Heter for Sha'atnez in Tzitzis). Even if mid'Oraisa it is permitted, mid'Rabanan it is Pasul due to Ta'aseh v'Lo Min ha'Asuy. If one attached Tzitzis on Shabbos b'Shogeg, this is even better than at night, which is Kosher. If he was Mezid, this requires investigation. If one designated a garment for the night, and made Tzitzis for it, and it was exempt (according to the Rosh), and later he designated it for the day, perhaps this is Ta'aseh v'Lo Min ha'Asuy, since it was exempt at the time. Or, perhaps it is Kosher, for no action needed to be done. This requires investigation.

Chachmas Shlomo (18:1): One may make Tzitzis at night. Rashi (Yoma 28a DH Zman) needed a verse to disqualify Shechitas Kodshim at night. We cannot learn from "b'Yom Tzavoso" (that one must offer during the day), for Shechitah is Hechsher Mitzvah (mere preparation). Regarding Tzitzis, there is no source to forbid Hechsher Mitzvah at night, since we hold that the Mitzvah is only wearing it.

Yabi'a Omer (8 OC 3): Ta'aseh v'Lo Min ha'Asuy disqualifies only when the object is intrinsically Pasul, e.g. a three cornered garment. It does not apply when the object later becomes Kosher automatically. Therefore, one may attach Tzitzis at night. If one put Schach on a Sukah under a roof, and later removed the roof, the Rema (626:3) is Machshir. Do not say that here is worse, for no action is done later to the Tzitzis to be Machshir them. Sefer ha'Michtam and the Me'iri require an action only if the Schach itself was Pasul.

Minchas Yitzchak (9:8:5): The Pri Megadim says that if one put at night, it is Kosher. This connotes that it is b'Di'eved. Maharsham permits l'Chatchilah, and Sha'arim ha'Metzuyanim b'Halachah brings this.

Yabi'a Omer (ibid. 3): Maharshag (2:74) did not understand the Pri Megadim's question. Attaching Tzitzis at night is like making a Sukah before Sukos. We need not say 'time comes by itself.' It is not clear that we say so. The Mishneh l'Melech was unsure about this. Nachalas Binyamin (12) and Pesach ha'Devir (1:18) asked why the Pri Megadim needed to learn from Ein Mechusar Zeman l'Bo b'Yom. We can learn from the Rema (626:3), who rules that Ta'aseh v'Lo Min ha'Asuy is only when the Pesul is in the Schach itself! I answer that the Pri Megadim teaches the law that Mechusar Zeman does not apply to the same day.

Yabi'a Omer (ibid. 4, citing Beis Meir OC 14): If one put Tzitzis on a borrowed garment within 30 days (which is exempt), he is Yotzei even after 30 days. This is not Ta'aseh v'Lo Min ha'Asuy, for no action was missing. This requires investigation. Toras Chayim (14:7) learned from the Pri Megadim that it is Kosher, for time comes by itself. Lev Chayim (3:29) permits inserting Tzitzis at night, for the Shulchan Aruch (19:1) says that the Mitzvah is wearing it. Therefore, it does not matter if one makes the Tzitzis at night. A woman is exempt from Tzitzis, yet she may make Tzitzis (OC 14:1). Also Chachmas Shlomo permitted because the Mitzvah is only wearing it. Some Poskim are concerned for the opinion that obligates Tzitzis on garments even when he is not wearing them. Therefore, Afikei Maginim (11) and Shulchan ha'Tahor say l'Chatchilah not to tie Tzitzis at night. However, Magen Giborim (19:3) says that there is no room for this stringency. Also, even if garments are obligated at all times, perhaps one may tie Tzitzis at night, for it is not Mechushar Ma'aseh. Keren l'David (3:6) says that Ta'aseh v'Lo Min ha'Asuy applies only when it is Mechushar Ma'aseh.

Yabi'a Omer (5, citing Pnei Mevin OC 14): Surely one may tie Tzitzis at night. Ta'aseh v'Lo Min ha'Asuy applies to a Sukah, yet clearly one should make a Sukah before Sukos, for one cannot make it on Yom Tov. (Note: one may add to a temporary Ohel even on Shabbos! Also, the Torah forbids Metaltelim only in the normal, skillful way. Seemingly, one must make a Sukah before Yom Tov in order that he can fulfill the Mitzvah immediately, or because we require a Sukah proper for seven days!) Similarly, we hold that Tzitzis is incumbent on the person, so it does not matter whether one makes them at night. In any case he is exempt when he makes them!

Yabi'a Omer (ibid.): Maharsham (on Orchos Chayim 18) permits tying Tzitzis at night, just like one may write Tefilin at night, even according to the Rambam (Hilchos Tefilin 4:1) who holds that there is no Mitzvah at night, and one who wears them then transgresses an Aseh. Levushei Serad (in Na'os Deshe) asked that Tzitzis should be Ta'aseh v'Lo Min ha'Asuy, since he was exempt when he made them, and an action (wearing them) is missing. He answered that making the Tzitzis is preparation for wearing it. Making and wearing are considered like one action. It is like a prolonged wearing. Wearing finishes the inserting of Tzitzis. Chasan Sofer (1 Sha'ar ha'Gedilim 34, 125b) says that since one cannot make a Sukah on Yom Tov, it is as if the Torah commanded to make it before Yom Tov. Similarly, one cannot tie Tzitzis the moment he wears it, so it is as if the Torah commanded to tie them beforehand. Even according to the opinion that Ta'aseh v'Lo Min ha'Asuy applies even when no action is needed, here sitting in the Sukah or wearing the garment is like a Ma'aseh Mitzvah itself. Chelek Levi (OC 11) learns from a borrowed garment, which is exempt for 30 days and obligated mid'Rabanan after 30 days. No Posek says that when he returns it to the owner, he must remove and tie the Tzitzis again because now it is obligated mid'Oraisa, and Ta'aseh v'Lo Min ha'Asuy applies! Rather, regarding this it is not like Mechushar Ma'aseh. The Rugatz'ove (Salmas Yosef 2) says that even according to the opinion that a Lulav must be tied, one may tie it before the Mitzvah applies (Sukah 33a). Also Salmas Chayim (28) and many others permit tying Tzitzis at night. There is no reason to be stringent about this.