"Rav Pada would tell you 'the end of of [the Mishna] states that R' Eliezer says he only negate 7 [days of his Nazirite count]" - Corresponding to the days that [a Naziritie would normally ] count, [and get sprinkled] on the third and seventh [day] because of impurity:

"And if you reason that [a Nazirite vow] needs to be 30 days, all [the days of his vow] should be negated." - Rather, this can't be, because the main Nazirite vow, according to R' Eliezer, is only 29 days. And why did R' Eliezer say that 7 days should be negated? It is because he needs to shave after he has been sprinkled [with purifying waters] on the 3rd and 7th days, as scripture says 'On the 7 day he should be shaved.' In principle, no days should need to be negated, since he [the Nazirite] has already counted 29 days in purity. But now, since he has been shaved while he is impure, a Rabbinic enactment goes into effect -

We learned: I am hereby a nazirite for 100 days; if he became impure on the one hundredth day, it negates the entire tally - and even according to Bar Padda, since he had said "100 days", he implies [100] complete [days].

And if it enters your mind that Rabbi Eliezer holds that part of the day is like an entire day, let seven days be negated - [seven days] and no more, if he became impure on the hundredth day, because when he became impure, his naziriteship was already past. And according to you[r reasoning], if he does not hold that part of the day is like an entire day, let all of [the days] be negated. Why then does he say "it negates only thirty days"?

Actually we do not say part of the day is like an entire day - and that which it says "it negates only thirty days" is a support for Bar Padda. And that which it says "and if he does not hold that part of the day is like an entire day", and the [term of naziriteship] has as of yet not been completed, why does it not negate all of them? [To that] Reish Lakish says, "this is the reason of Rabbi Eliezer" etc.

"This is the law of the nazirite on the day when the days of his consecration are complete" - whether it be a term of naziriteship of thirty days, or whether it be a term of naziriteship of 100 days, give him the halakha of a[n unspecified] nazirite, which is thirty days; and thus he says "it negates only thirty days".

What are the days that require completion? You must say thirty - because a lunar month is only twenty-nine and one half [days], and sometimes it must be "completed" to thirty. This would exclude other [quantities of] days [such as] twenty and forty, which do not need "completion". [What, is it not the case that Rav Mattena said his opinion in accordance with Rabbi Yoshiya - who said explicitly that there is no shaving before thirty days? And Bar Padda, who said for the number of days which need completion -] which implies that there should be a naziriteship on those days which need "completion"; of which how many? Twenty-nine.

Rabbi Yoshiya holds - that which it is written "until [the days] are complete" implies up to, but not including, thirty days. Therefore we need [the verse] "grow long" [to teach us that] there is no growth of hair in under thirty [days].

And Rabbi Yonatan holds "until" means until and including - and we do not need "grow long", since he derives [the rule of thirty-day naziriteship] from "until [the days] are complete".

The master said: What are the days that require completion? You must say thirty - which implies that an unspecified naziriteship is thirty days.

But say it is referring to a week - let an unspecified naziriteship be a week, which is six days with the seventh day coming to complete the week. But say that "until the days are complete" means "until a week is complete".

Is there ever [a week that is] lacking - [that is,] which needs "completion"? All weeks are equal, and for this reason we cannot say that the verse is referring to them. But a month, for which [it can be said that] there is "lacking", since there are lacking [months] and full [months], you can say that the verse is referring to [only] months.