Mishnah 5 in Maseches Nedarim deals with a person who makes a vow that depends on the falling of rain. The rainy season in Eretz Yisrael is divided into different periods - the yoreh, the early rains, and the malkosh, the later rains - and even within the early rains themselves there are distinct times.
One who vows "until the rains":
The Mishnah rules that his intention is "ad shetered revi'ah sheniyah" - until the second rainfall comes down.
When is the time of the second rainfall? On this itself the Tanna'im disagree:
The seventh of Marcheshvan.
The seventeenth of Marcheshvan.
The twenty third of Marcheshvan.
Rabban Shimon ben Gamliel says that the matter does not depend on the second rainfall actually coming down; rather, "ad sheyagia zemanah shel revi'ah" - it is enough that the time of that period has arrived, even if no rain has fallen. According to this view as well, the dispute remains as to which day in Marcheshvan is meant.
One who vows "until the rains stop":
Rabbi Meir: until all of Nissan has passed - until the entire month of Nissan has gone by.
Rabbi Yehudah: until Pesach has passed, and there is no need for the whole month of Nissan to pass.
A vow that depends on the year and on the month of Adar:
One who says "konam yayin she'eini to'em hashanah" - wine is forbidden to me like a sacrifice, that I will not taste it this year - and the year was made a leap year, meaning that beis din added an extra month of Adar to it, is forbidden in it and in its added month. That is, the wine is forbidden to him both during the regular months of the year and during that additional month.
One who vows "ad rosh Adar" - his intention is until the beginning of the first Adar, and one who vows "ad sof Adar" - until the end of the first Adar.
The Gemara explains that our Mishnah is dealing with someone who did not know at the time of his vow that the year was going to be made a leap year, as was the case in the days when the decision to add a month was entrusted to beis din, before the fixed calendar was established. Under these circumstances, since he did not know that there would be a second Adar, his intention is to the first Adar. But if he knew in advance that the year would be made a leap year, Rabbi Meir holds that "the end of Adar" means the end of the second Adar, and not as our Mishnah states, the end of the first Adar.
One who vows against wine until Pesach:
Rabbi Yehudah says: although generally one who says "until Pesach" means until the entire festival has passed, here, since he explicitly mentioned wine, he is forbidden only until the night of Pesach. The reason: a person's intention is only until the time when people normally drink wine, and on the night of the Seder everyone drinks wine as part of the mitzvos of the night. Therefore, in this case his intention is to the beginning of Pesach and not to its end.
In summary: in this Mishnah we learned the time measures of vows that depend on rains and on months - "until the rains" means until the second rainfall (and according to Rabban Shimon ben Gamliel, until its time arrives), "until the rains stop" means until Nissan has ended according to Rabbi Meir, or until Pesach has passed according to Rabbi Yehudah, one who vows "this year" is forbidden in it and in its added month, and one who vows until the beginning of Adar or until its end means the first Adar when he did not know about the leap year. And we saw that mentioning wine in the vow reveals the intention of the one who vows and limits the vow to the night of Pesach.