This section is reserved for Judaism's own testimony concerning their Babylonian timekeeping practice. As such, any testimony within the Judaism brand is legitimate. Canonical texts, non-canonical texts, extra-biblical historical texts, apocryphal, pseudepigraphical, etc. are all legitimate candidates for this section. There is an abundant supply of source material in Judaism's writings, including the Mishna and the Gemara (Babylonian Talmud).
Sanhedrin Folio 11a
Our Rabbis taught: A year cannot be intercalated unless the Nasi sanctions it. It once happened that Rabban Gamaliel was away obtaining permission from the Governor in Syria and as his return was delayed, the year was intercalated subject to Rabban Gamaliel's later approval. When Rabban Gamaliel returned he gave his approval with the result that the intercalation held good.
Our Rabbis taught: A year may not be intercalated except where it is necessary either for [the improvement of] roads or for [the repair of] bridges, or for the [drying of the] ovens [required for the roasting] of the paschal lambs, or for the sake of pilgrims from distant lands who have left their homes and could not otherwise reach [Jerusalem] in time. But no intercalation may take place because of [heavy] snows or cold weather or for the sake of Jewish exiles [from a distance] who have not yet set out.
Our Rabbis taught: The year may not be intercalated on the ground that the kids or the lambs or the doves are too young. But we consider each of these circumstances as an auxiliary reason for intercalation. How so?
R. Jannai [gave the following example of the law in operation], quoting from R. Simeon b. Gamaliel's [letter to the Communities]: 'We beg to inform you that the doves are still tender and the lambs still young, and the grain has not yet ripened. I have considered the matter and thought it advisable to add thirty days to the year.
An objection was raised: How long a period was intercalated in the year? Thirty days. R. Simeon b. Gamaliel said: A month? — R. Papa Said: [The matter is left to the judgment of the intercalary court:] if they wish, they may add a month; or if they wish thirty days. - Babylonian Talmud: Sanhedrin Folio 11a
Sanhedrin Folio 11b
It once happened that Rabban Gamaliel was sitting on a step on the temple hill and the well known scribe Johanan was standing before him while three cut sheets were lying before him. 'Take one sheet', he said, 'and write an epistle to our brethren in Upper Galilee and to those in Lower Galilee, saying: "May your peace be great! We beg to inform you that the time of 'removal' has arrived for setting aside [the tithe] from the olive heaps." Take another sheet, and write to our brethren of the South, "May your peace be great! We beg to inform you that the time of 'removal' has arrived for setting aside the tithe from the corn sheaves."
And take the third and write to our brethren the exiles in Babylon and to those in Media, and to all the other exiled [sons] of Israel, saying: "May your peace be great for ever! We beg to inform you that the doves are still tender and the lambs still too young and that the crops are not yet ripe. It seems advisable to me and to my colleagues to add thirty days to this year."' [Yet] it is possible [that the modesty shown by Rabban Gamaliel in this case belongs to the period] after he had been deposed [from the office of Nasi].
Our Rabbis taught: A year may be intercalated on three grounds: on account of the premature state of the corn-crops; or that of the fruit-trees; or on account of the lateness of the Tekufah. Any two of these reasons can justify intercalation, but not one alone. All, however, are glad when the state of the spring-crop is one of them.
Rabban Simeon b. Gamaliel says: On account of [the lateness of] the Tekufah. The Schoolmen inquired: Did he mean to say that 'on account of the [lateness of the] Tekufah' [being one of the two reasons], they rejoiced, or that the lateness of the Tekufah alone was adequate reason for intercalating the year? The question remains undecided.
Our Rabbis taught: [The grain and fruit of the following] three regions [are taken as the standard] for deciding upon the declaration of a leap-year: Judea, Trans-Jordania, and Galilee. The requirements of two of these regions might determine the intercalation, but not those of a single one. All, however, were glad when one of the two was Judea, because the barley for the Omer was obtained [by preference] in Judea.
Our Rabbis taught: The intercalation of a year can be effected [by the Beth din] only in Judea; but if for some reason [it had been decided upon by the Beth din] in Galilee, the decision holds good. Hanania of Oni, however, testified: 'If the intercalation was decided upon in Galilee, it is not valid.'
R. Judah the son of R. Simeon b. Pazi asked: What is the reason for the view of Hanania of Oni? Scripture states, Unto His habitation shall ye seek and thither thou shalt come: whatever search you have to make shall be only in the habitation of the Lord.
Our Rabbis taught: A leap-year is to be declared only by day, and if it has been declared by night, the declaration is invalid. The sanctification of a month is to be performed by day, and if it has been performed by night it is not valid. R. Abba says: What passage [proves this]? - Blow the horn at the new moon, at the covering of the moon our feast-day. Now on which feast is the moon covered? We must say on the New Year. And it is thereupon written, For this is a statute for Israel, a judgment of the God of Jacob: Just as judgment is executed by day, so also must the sanctification of the month take place by day.
Our Rabbis taught: A year is not to be intercalated... - Babylonian Talmud: Sanhedrin Folio 11b (ctd. in Folio 12a)
Sanhedrin Folio 12a
...in years of famine. It has been taught:
Rabbi says: A man came from Baal Shalisha and brought to the man of God bread of the first fruits; twenty loaves of barley, [bread of the newly ripened crop]. Now, there was no other place in Palestine where the fruit ripened earlier than in Baal Shalisha; yet, according to this account, only one species had ripened there [by that date]. If you suggest that it was wheat, the text reads 'barley'. If again you suggest that it was ripened before the bringing of the Omer, the text reads further: Give unto the people that they may eat, which must have been after the bringing of the Omer. We may conclude therefore that the year should have been intercalated. But why did Elisha not do so? For the reason that it was a year of famine and all hastened to the threshing floor [to procure food].
Our Rabbis taught: The year may not be intercalated before the New Year, and if it be intercalated, the intercalation is invalid. In case of necessity, however, a year may be intercalated immediately after the New Year; yet even so, only a [second] Adar is added. But is this really so? Was not a message once sent to Raba: 'A couple [of scholars] have arrived from Rakkath who had been captured by an eagle whilst in possession of articles manufactured at Luz, such as purple, yet through divine mercy and their own merits they escaped safely. Further, the offspring of Nahshon wished to establish a Nezib, but yon Edomite would not permit it.
The Members of the Assembly, however, met and established a Nezib in the month in which Aaron the Priest died'? Yes, the calculations were indeed made, but not published [until after the New Year]. How was it implied that the term Nezib [mentioned in the message] connoted 'month'?
Because is is written, Now Solomon had twelve officers [Nezibim] over all Israel who provided victuals for the king and his household; each man his month in the year. But is it not written, and one officer [Nezib] that was in the land?
Rab Judah and R. Nahman, one holds that one single officer was appointed over all [the other officers]: the other is of the opinion that this refers to the [special officer in charge of the provisions during] the intercalated month.
Our Rabbis taught: We may not, in the current year, intercalate the following year, nor intercalate three years in succession. R. Simeon said: It once happened that R. Akiba, when kept in prison, intercalated three years in succession. The Rabbis, however, retorted: 'Is that your proof? The court sat and intercalated each year at its proper time.'
Our Rabbis taught: We may not intercalate a Sabbatical year nor the year following a Sabbatical year. But which year was it usual to intercalate? That preceding the Sabbatical year. Those of the House of Rabban Gamaliel, however, used to intercalate the year following the Sabbatical year. And this enters into the dispute of the following Tannaim. For it has been taught: Herbs may not be imported from outside the land [of Israel]. But our Rabbis permitted it.
Wherein do they differ? R. Jeremiah said: They differ as to whether we apprehend lest the earth attached to them [should also be imported].
Our Rabbis taught: We may not intercalate a year because of uncleanness. R. Judah said: We may intercalate. R. Judah observed: It once happened that Hezekiah king of Judah declared a leap year because of uncleanness, and then prayed for mercy, for it is written, for the multitude of the people, even many of Ephraim and Manasseh, Issachar and Zebulun had not cleansed themselves... - Babylonian Talmud: Sanhedrin Folio 12a (ctd. in Folio 12b)
Sanhedrin Folio 12b
...yet did they eat the Passover otherwise than it is written, for Hezekiah had prayed for them, saying: May the Lord in His goodness pardon everyone. R. Simeon said: If the intercalation was actually on the ground of uncleanness, it holds good. Why then did Hezekiah implore Divine mercy?
Because only an Adar can be intercalated and he intercalated a Nisan in Nisan. R. Simeon b. Judah said on behalf of R. Simeon, that it was because he had persuaded Israel to celebrate a Second Passover [unduly]. The Master has said: 'R. Judah said: We may intercalate [on the ground of uncleanness].'
Hence R. Judah holds that [the law of] uncleanness, in the case of an entire community, is only suspended [and not abrogated]. But has it not been taught: The ziz, whether it is on his [the Priest's] forehead or not, propitiates.
So said R. Simeon, R. Judah said: Only when it is on his forehead does it propitiate, but not otherwise. R. Simeon thereupon said to him: The case of the High Priest on the Day of Atonement affords proof, seeing that it propitiates even when it is not worn on his forehead.
And R. Judah answered him: Leave the Day of Atonement aside, for the [laws concerning] impurity are entirely abrogated in the case of a whole Community? But even according to this reasoning, is there not a contradiction within the passage itself?
[Thus:] R. Judah said: We may intercalate [on account of uncleanness]; and then he himself relates what happened in the case of Hezekiah, king of Judah, who intercalated a year because of uncleanness, but implored Divine mercy on himself [for his action]? But the text is evidently defective, and should read as follows: 'We may not intercalate a year on account of uncleanness, but if it has been intercalated, the decision holds good.
R. Judah maintained that the intercalation is not valid, and R. Judah observed: It once happened with Hezekiah etc...
But if so, [when] R. Simeon says: If the year is intercalated for the sake of [avoiding] uncleanness, the decision holds good, is [he not merely repeating] the opinion of the first Tanna? Said Raba: They differ as to whether [it may be intercalated] at the outset.
It has been taught likewise: A year may not be intercalated at the outset because of uncleanness. R. Simeon said: It may be intercalated. Why then did he [Hezekiah] pray for mercy? Because only an Adar can be intercalated, whereas he intercalated a Nisan in Nisan.
The Master has said: 'Because only an Adar can be intercalated, whereas he intercalated a Nisan in Nisan.' But did not Hezekiah agree [that the verse], This month shall be unto you the beginning of months,[implies], only this month can be Nisan [once proclaimed], and no other?
He erred on a ruling of Samuel, for Samuel said: The year is not to be intercalated on the thirtieth day of Adar, since it is eligible to be appointed [the first day of] Nisan. He [Hezekiah] however thought that we do not consider its eligibility [to belong to Nisan]. It has been taught likewise: The year may not be intercalated on the thirtieth day of Adar, since it is eligible to be appointed [the first day] of Nisan.
[It was stated above:] 'R. Simeon b. R. Judah said on behalf of R. Simeon that it was because he had [wrongfully] persuaded the people to celebrate a Second Passover [that Hezekiah prayed to be forgiven].'
How did it happen? R. Ashi said: E.g., half of Israel were clean and half unclean, but the women made up the number of the clean and turned it into a majority.
Now, at first he held that women too are bound [to offer the lamb] on the first [Passover], so that only a minority was unclean; and a minority is relegated to the Second Passover. But later he adopted the view [that the participation of] women in the First [Passover celebration] is only voluntary, so that the unclean were in a majority, and a majority is not relegated to the Second Passover.
The text [states]: 'Samuel said, The year is not to be intercalated on the thirtieth day of Adar, since it is eligible to be appointed [the first day of] Nisan.' But what if it were intercalated? 'Ulla said: The month must not be sanctified. But what if it were sanctified? Raba said: Then the intercalation is invalid. R Nahman said: Both the intercalation and the sanctification are valid.
Raba said to R. Nahman: Let us consider! Between Purim and the Passover there are thirty days, and from Purim we begin to lecture on the laws of Passover, as has been taught: People must begin to inquire into the Passover laws thirty days before the Festival.
R. Simeon b. Gamaliel said: A fortnight before. If, then, it [sc. Passover] is postponed at the beginning of the month [of Nisan], people will be liable to disregard the law regarding leaven [on Passover]. He [R. Nahman] answered him: It is well-known that the intercalation of a year depends on [minute] calculations, hence they would say that [the declaration was not made until the thirtieth day] because the Rabbis had not completed their calculation until then.
Rab Judah said in Samuel's name: A year is not to be intercalated unless the [summer] Tekufah is short of completion by the greater part of the month. And how much is that? Sixteen days: so holds R. Judah. - Babylonian Talmud: Sanhedrin Folio 13a (ctd. in Folio 13b)
Sanhedrin Folio 13a
R. Jose said: Twenty-one days. Now, both deduce it from the same verse, and the feast of ingathering at the tekufah [season] of the year. One master holds that the whole Feast [of ingathering] is required to be included [in the new Tishri tekufah; the other, that only a part of the festival [of ingathering] must [be included].
Now, which view do they adopt? If they hold that the tekufah day is the completion [of the previous season]: then, even if it were not so, it will meet with the requirement neither of him who holds that the whole Festival [must be included,] nor of him who holds that only part of it [is necessary]! One must say therefore that they both hold that the tekufah day begins.
An objection is raised: The tekufah day concludes [the previous season]: this is R. Judah's view. R. Jose maintains that it commences [the new]. Further has it been taught: A year is not intercalated unless the [summer] tekufah is short of completion by the greater part of the month.
And how much is that? Sixteen days. R. Judah said: Two thirds of the month. And how much is that? Twenty days.
R. Jose ruled: It is to be calculated thus: [If there are] sixteen [days short of completing the tekufah] which precedes Passover, the year is to be intercalated. [If, however, there are] sixteen [short of completing the tekufah] which precedes the feast [of tabernacles], the year is not to be intercalated.
R. Simeon maintained: Even where there are sixteen [days short of completing the tekufah] which precedes the feast [of tabernacles], the year is intercalated. Others say [that the year is intercalated even if the tekufah is short of completion] by the lesser part of the month. And how much is that? Fourteen days? The difficulty remained unsolved. <---- lol (I couldn't resist. - Scot)
The master has said: 'R. Judah said: Two thirds of the month. And how much is that? Twenty days. R. Jose ruled: It is to be calculated [thus: if there are] sixteen [days short of completing the tekufah] which precedes Passover, the year is to be intercalated.'
But is not this view identical with R. Judah's? They differ as to whether the tekufah day completes [the previous] or begins [the new cycle]. The master has said: '[R. Jose holds that] if there are sixteen [days short of completing the tekufah] which precedes the feast [of tabernacles], the year is not intercalated.'
According to R. Jose, then, only if there are sixteen [days short of completing the tekufah] preceding the feast [of tabernacles is intercalation] not [permitted]; but if there are seventeen or eighteen [days short], the year is intercalated.
But has he not himself said: If there are sixteen [days short of completing the tekufah] which precedes Passover, we may intercalate, but not if less? But no; in neither case may we intercalate. But seeing that he spoke of the number sixteen [with regard to the tekufah] preceding Passover, he gives it also [in connection with the tekufah] preceding the feast [of tabernacles].
[It was stated above]: 'R. Simeon maintained: Even where there are sixteen [days short of completing the tekufah] which precedes the feast [of tabernacles], the year is intercalated.' But is not this view the same as that of the first Tanna? - Babylonian Talmud: Sanhedrin Folio 13a (ctd. in Folio 13b)
Sanhedrin Folio 13b
They differ as to whether the tekufah day completes [the previous season] or begins [the new season]. But their views were not defined.
'Others say: [That the year is intercalated even where there is a shortage] by the lesser part of the month. And how much is that. Fourteen days.'
Now, which view do they adopt? Do they hold that the tekufah day completes [the previous season], and that we require the whole feast [of ingathering to be included in the new tekufah?] But surely in our case, it is so. [Why then intercalate?]
The 'Others', says R. Samuel son of R. Isaac, speak of the Nisan tekufah, for it is written, observe the month of aviv [spring]; i.e., take heed that the beginning of the vernal tekufah shall occur on a day in Nisan when the moon is still in the process of renewal.
But why not intercalate a day in Adar?
R. Aha b. Jacob said: The Tanna reckons from higher numbers downward, and says as follows: [If there is a deficiency] as far as [i.e., by more than] the lesser part of the month, the year is intercalated. And how much is that? Fourteen days.'
Rabina said: In reality, the 'Others' refer to the Tishri Tekufah, but they hold that the whole feast [of ingathering] must fall [in the new tekufah] including also the first [day of the Feast].'[Including] the first day'?
But is it not written, the feast of ingathering [shall be] at the tekufah of the year; [meaning the day on which ingathering is permitted]? [They interpret it as] 'The Feast which occurs in the season of ingathering.' - Babylonian Talmud: Sanhedrin Folio 13b