Good Chodesh -- chodesh ha'geulah! Time to focus on Pesach!
The Minchas Chinuch has a tremendous chiddush (Mitzvah 2:22 in the new editions): The mitzvah of milah can only be done on the 8th day and not earlier, and can only be done during the day, but never at night. M.C. writes that if someone were to cut off the orlah of the baby at night or before the 8th day, they have not done anything wrong. When the 8th day or daylight comes, the baby will have no orlah so there will be no mitzvah to do, but so what? Who says there is anything wrong with removing the opportunity to do a mitzvah before the mitzvah kicks in?
He contrasts this with the din by korban pesach, where the gemara (Pesachim 41a) darshens the command to eat korban pesach at night, "v'achlu es ha'basar ba'layla ha'zeh," as implying that there is a prohibition of eating the korban earlier (according to Rambam it is an issur aseh; according to Ramban it is an actual lav), before night. We never find a similar derasha that "bayom ha'shmini" prohibits cutting off the orlah earlier, so we have no right to invent such a din.
Cutting off the orlah before the mitzvah kicks in is like rounding off the corner of a garment so it does not have 4 corners and is exempt from tzitzis. The gemara says that at times of Hashem's anger avoiding the mitzvah is not a good thing to do, but otherwise, there is no issur.
Shu"T Chavatzles haSharon (Y.D. 78) points out that the M.C. seems to contradict himself. The din is that someone who is "b'derech rechoka" (machlokes Tanaim what the shiur is) is patur from korban pesach and gets pushed off to pesach sheni. The Tzlach writes that a person who lives far away and fits the category of "derech rechoka" doesn't have to do anything about his situation -- the Torah exempts him from any chiyuv. Minchas Chinch (5:13 in the new edition) disagrees. M.C. goes back and forth trying to prove his point from various Rishonim (see Rashi d"h onesh kareis Pesachim 69a which implies that before 6 hours of the day "lo ramya chiyuva alei," there is no issur kareis, but there is a chiyuv to try to being the korban), but his strongest argument in the end is based on logic. A person has a mitzvah to be noteil lulav, hear shofar, eat matzah. Can a person just sit back and do nothing and then when R"H, or Sukkos, or Pesach comes, claim that they are not responsible for not doing the mitzvah because they lack the means to do so? Of course not! Each mitzvah implicitly requires that a person make the needed effort **beforehand** to have the means to fulfill it in the proper time. So too when it comes to korban pesach, a person who lives outside Yerushalayim has to make an effort to travel there so that when 14 Nissan comes he has the means to fulfill his obligation, not sit home and do nothing and claim an exemption.
By the very same logic, argues the Chavatezels haSharon, shouldn't a person have to avoid cutting off the baby's orlah in advance so that when the proper time comes, he can fulfill the mitzvah of milah? Isn't that part and parcel of making sure one has the means to do the mitzvah once its time comes?
Ad kan the kashe of the Chavatzelesh haSharon (who BTW took over as Rav in Tarnipol after the M.C.'s son).
I am just going to add 2 trivial cents: Tos RI"D (Kiddushin 29) holds that the mitzvah of milah is not classified as zman gerama (see Tos Kid 29a, and R' Chaim in the stencils) because even though cutting the orlah can only be done during the day, the mitzvah is actually to make all the necessary preparations for that to happen (e.g. hiring a mohel, ordering the bagels, etc. : ), and those preparations can be done both by day and at night. Cutting off the orlah ahead of time would surely seem to negate the chiyuv to prepare for the mitzva. What I don't understand is if there is an implicit obligation by every mitzvah to make sure one has the means to fulfill it, as M.C. writes by k.p., what is the chiddush of milah acc to Tos RI"D?
Final note: no, I am not a super baki that knows the Shu"T Chavatzeles haSharon, but R' Ovadya was, and he refers to it in Yabi'a Omer 6 23:3
Nu, so Nisan is here -- go out and start shopping and cleaning to make sure you have the means to do all the mitzvos of leil ha'sder b'hidur!