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?