
SUMMARY
If someone takes upon himself two consecutive Neziruyos if he shaves for the first Nezirus on the thirtieth day he may shave for the second Nezirus on the sixtieth day. According to Rav Masna the thirtieth day of the first Nezirus counts both as the last day of the first Nezirus and the first day of the second Nezirus. If he shaves for the first Nezirus on the thirtieth day and for the second Nezirus on the fifty ninth day he is Yotzei b'Di'eved. (1) The Tana Kama holds that if a Stam Nazir becomes Tamei on the thirtieth day he must start his Nezirus from the beginning. (2) R. Eliezer holds that if a Stam Nazir becomes Tamei on the thirtieth day he only must wait seven days before bringing his Korbanos. (3) The Tana Kama says that if someone is a Nazir for 100 days and he becomes Tamei on the one hundredth day he must recount his Nezirus from the beginning. R. Eliezer says that if he becomes Tamei on the one hundredth day he only must recount 30 days. (4) R. Yoshiyah learns out from the numerical value of Yiheyeh that a Stam Nezirus is for thirty days. R. Yonasan learns out that a Stam Nezirus is for thirty days from the Pasuk that says Ad Melos ha'Yamim.
A BIT MORE
1. The fifty ninth day is the thirtieth day of the second Nezirus and therefore b'Di'eved he may shave on the fifty ninth day both according to bar Pada and R. Masnah. 2. According to Bar Pada even though the Nezirus is completed in 29 days the Rabanan decreed that if he becomes Tamei on the twenty ninth day that he must restart his Nezirus because sometimes a person says that he will be a Nazir for 30 complete days and in that case the thirtieth day is included in the Nezirus. 3. Since the thirtieth day is the end of his Nezirus he does not have to recount his Nezirus and he only must wait seven days until he becomes Tahor before he brings his Korbanos. 4. It is a Gezeiras ha'Kasuv according to R. Eliezer that if a Nazir becomes Tamei on the last day of his Nezirus that he only must recount thirty days.

BRIEF INSIGHT
KORBANOS B'TUM'AH R. Eliezer holds that if a Stam Nazir becomes Tamei on the thirtieth day he only must wait seven days before bringing his Korbanos. He must wait seven days because he must be Tahor when he brings his Korbanos. The Rosh asks why does he have to be Tahor to bring his Korbanos. Why can't he send his Korbanos to the Beis ha'Mikdash while he is Tamei? The Rosh answers that a Nazir must enter the Azarah when he brings his Korban because the Pasuk says that the Zero'ah b'Sheilah of his Shelamim shall be placed on the hands of the Nazir. Therefore the Nazir must be Tahor so that it can be placed on his hands.
QUICK HALACHAH
TWO NEZIRUYOS If someone takes upon himself two consecutive Neziruyos he should shave for the first Nezirus on the thirty first day and for the second Nezirus on the sixty first day. If he shaves for the first Nezirus on the thirtieth day he may shave for the second Nezirus on the sixtieth day. If he shaves for the second Nezirus on the fifty ninth day he is Yotzei because the thirtieth day counts for the first day of the second Nezirus. (Rambam Hilchos Nezirus 4:2)
