Avodah Zarah, Chapter 1, Mishnah 3. After the general rules taught earlier, the Mishnah now goes on to specify the particular festivals it has in mind. These were festivals that formed part of the Roman culture prevalent in Eretz Yisrael in the second century, the era of the Mishnah. Today these festivals are lost to us and no longer familiar, but it is fitting to apply these teachings to any pagan festival observed in whatever place a person happens to live.
"V'eilu eideihen shel ovdei kochavim":
This is the list of specific festivals to which the Mishnah refers:
"Kalenda" - according to the Bartenura, the eight days following the winter solstice. If we place the winter solstice on the twenty second of December, this means the twenty third of December through the thirty first.
"V'Saturnura" - a separate festival: the eight days preceding the winter solstice, which is the shortest day of the year.
The Bartenura brings from the Gemara that these are pagan festivals whose origins reach all the way back to the days of Adam. After the sin, the world began to grow darker as the days grew shorter, and Adam was alarmed that the world might be coming to an end. The word solstice is made up of 'sol' - sun, and 'stice', from stasis - to stand still; this is the turning point after which the days begin to lengthen again, and the sun no longer dips so far toward the western horizon.
Once Adam saw that the world was not coming to an end, but that this is simply the way of the world - days lengthen and days shorten - it became a celebration in its own right: during the first eight days he prayed that the world should not come to an end, and afterward he celebrated that it had not come to an end. The gentiles and idol worshippers seized upon this and made these into festivals of their own.
It is worth noting that in outside sources we find that the Roman Empire had a festival called Kalenda, which was the first day of the Roman month. It emerges that there were about twelve Kalenda days a year, the first of each month, and this was considered an especially fitting time for the repayment of debts - and for that reason it was a day on which it was particularly bad to do business with them. So this was a small celebration each and every month during the period of the Roman Empire.
"Saturnura" is harder to locate in those sources. There is a separate, well known festival called Saturnalia, whose name derives from 'Saturn', the name of a pagan deity and also the name of a planet in our own day. It was a seven day festival around the winter season, celebrated every year with wild revelry and carnival-like abandon.
Yom Kratesim and the royal days:
"Yom Kratesim" - according to the Bartenura, the anniversary of the Roman victory over the Greeks, the Greek Empire. This may be an allusion to the year 167 BCE, when the Romans defeated the Macedonian Empire in the Third Macedonian War.
"V'yom genusia shel melachim" - the coronation day of a new emperor.
"V'yom haleidah" - the emperor's birthday.
"V'yom hamisah" - the anniversary of his death. These days were added in the words of Rabbi Meir.
These days were celebrated throughout the empire as a tribute to the emperor, who in various times and places was himself regarded as a kind of deity.
The view of the Chachamim - "Kol misah sheyesh bah sereifah":
"VaChachamim omrim: kol mitah she'yesh bah sereifah - yesh bah avodah zarah" - according to the Sages it depends: not every anniversary of an emperor's death and the beginning of his son's reign counts as a pagan holiday. If they practiced burning - that is, they took the deceased emperor's belongings and burned them, which indicates that he was so exalted that it would be improper for anyone else to possess his things - then he has the status of a semi-deity, and the anniversary of his death is considered a pagan holiday and a festival that we have prohibited as such.
"Ve'she'ein bah sereifah - ein bah avodah zarah" - the anniversary of the death of an emperor whose belongings were not burned when he died proves that he was not so important in their eyes, and no such idolatrous attachment was formed with him. Therefore the restrictions of avodah zarah do not apply to it.
Private holidays of the individual:
Beyond this, the Mishnah says, there is the possibility that any given person has his own private, personal holiday, based on events that occurred in his own life. On that day it is forbidden to do business with him, even though the rest of society is not celebrating and is open for business as far as halachah is concerned:
"Yom tiglachas zekano u'valorito" - the day on which the idolater shaves his beard and his blorit, the lock of hair at the back of his head that he was accustomed to grow, as a sort of annual event. This is a personal celebration and an event of avodah zarah, and therefore it is forbidden to do business with him, to lend to him or to borrow from him on his private holiday.
"Ve'yom she'alah bo min hayam" - the day on which he returned from a sea voyage, which is of course extremely dangerous.
"Ve'yom she'yatza bo mi'beis ha'asurim" - the same law applies to the day he was released from prison. He goes off to celebrate, and this is a personal holiday for him; it is forbidden to do business with him, lest he attribute what happens to him to his personal deity.
"Ve'oved kochavim she'asah mishteh li'vno" - a wedding feast that the gentile makes for his son. It appears that the early authorities did not have this portion of the Mishnah, and it apparently came from a beraisa elsewhere and does not originally belong to the Mishnah; in any case, the very same idea applies here as well.
"Eino asur ela oso hayom ve'oso ish bilvad" - on all of those days restrictions apply, but they are limited to that particular person and to the particular day of his celebration alone. Other people around him, as well as the days preceding his celebration, are not restricted at all with regard to doing business, buying, selling, lending and the like.