Nedarim

Rabina said: Meremar told me: Thus said your father in R. Joseph's name: With whom does this statement of R. Jeremiah b. Abba agree? With R. Nathan. For it was taught: R. Nathan said: Whoever vows is as though he built a high place, and who fulfils it, is as though he burnt incense thereon. THIS SABBATH, HE IS FORBIDDEN THE WHOLE WEEK [AND THE SABBATH BELONGS TO THE PAST]. This is obvious? — I might think that he meant the [week] days of the Sabbath:  we are therefore taught [otherwise]. 'THIS MONTH,' HE IS FORBIDDEN THE WHOLE OF THAT MONTH, BUT THE BEGINNING OF THE [FOLLOWING] MONTH BELONGS TO THE FUTURE. This is obvious? — It is necessary only when the [following] Month is defective: I might think that the new Moon belongs to the past, and is forbidden: it is therefore intimated that people call it new moon. 'THIS YEAR,' HE IS FORBIDDEN THE WHOLE YEAR. The scholars propounded: What if one vows, 'Konam, if I taste wine a day'? is its law as 'to-day' or 'one day'? — Come and hear [a solution] from our Mishnah. 'KONAM, IF I TASTE WINE TO DAY HE IS FORBIDDEN WINE ONLY UNTIL IT GETS DARK; hence 'a day' is as 'one day'! Then consider the second clause: IF HE SAYS, 'ONE DAY,' HE IS FORBIDDEN FROM DAY TO DAY: hence a day' is as 'to-day'?  Thus nothing can be deduced from this. R. Ashi said, Come and hear: 'Konam, if I taste wine this year,'  if the year was intercalated, he is forbidden for the year and the extra month. How is this meant?