#8 and #9 in Mi Yodeya song

Question

Item #8 in the Haggadah song Mi Yodeya sems different then the item assigned for any of the other numbers.

All the other items can be individually counted. For example - 4 mothers, 3 fathers, 12 tribes, 11 stars, etc.

item #8 says שמונה ימי מילה which seemss to translate as "Eight days of circumcision". Actually there is just ONE day of circumcision. You count 8 days untill you arrive at the day of circumcision. But, it still occurs just one a single day.

item #9 would be a similar problem. Translated literally it measn "9 months of birth" shouldn't it say תשעה ירחי הריון - "Nine months of pregnancy?"

Is this a mistranslation, an "exception" to the inidvidual quantity that occurs with the other items? What is happening?

Answer 1

All sources cited below are from the Oz V'hadar Mesivta Haggadah (p. 232, ft. 13 and 15; p. 824-825). Interestingly, while they do say as you did that שבעה ימי שבתא means "seven days of the week," their various answers to שמונה ימי מילה all directly address שבעה ימי שבתא as well.

All of the answers they quote regarding תשעה ירחי לידה answer a different question: if all of the things in the piyut are unique to the Jews, or a merit by which they left Mitzraim, then why is nine months of pregnancy listed as well? I've only referenced below the ones which can be used to answer your question as well.

1. The Sifsei Yitzchak answers your question about eight days of Milah based on the comments of the Ohr Zarua (Shu"t §11) and Tosfos Rid (Kiddushin 29a), who write that the Mitzvah of Milah is not only to circumcise the child, but also to prepare for it from the time the baby is born. Thus, all of his first eight days can be considered part of the Mitzvah. Similarly, שבעה ימי שבתא means that since one prepares for Shabbos all week, it's all considered part of the Mitzvah.)
   The Sha'ar Yisachar (Ma'amarei Chodesh Nissan, Ma'amar Agadeta d'Pischa, §133) explains the relevance of nine months of pregnancy that the Jews observed Hilchos Niddah, and so they, unlike the other nations, could clearly determine when the nine months began and ended. Perhaps based on this we can answer your question by combining it with the above: since the nine months were spent observing halachos in preparation of the births, they can be ascribed to the birth at the end.
2. Rav Moshe Feinstein explains that for many mitzvos, at the time at which one is not performing the mitzvah, the effects of the mitzvah aren't apparent. Not so Bris Milah and Shabbos; the former is always apparent, and it's for the latter that one works all week. Perhaps similarly we can say that all nine months of pregnancy are for the birth which follows.
3. Rav Yosef Shlomo Kahanneman of Yeshivas Ponevezh is quoted as having said that the night of the Seder is meant to strengthen our Emunah. He explains the line to mean that "nine months [of pregnancy]" are required for a "birth," to reject the claims of the Christians who believe that "that man" wasn't born in the way normal people are. (Indeed, in the footnotes, they quote the Mahari"l Minhagim, Likutim §103, that Jesus is called "that man" to indicate that he was a man just like any other, and he was not Divine.)
   While the part about strengthening our Emunah doesn't extend to Bris Milah, the main answer does: Bris Milah is only possible if there are (at least) eight days leading into it.