One week from today is that day, and inquiring minds want to know: Is Friday the 13th good or bad for the Jews?

Friday the 13th of course, is that terrible, scary, frightening day filled with mischief, mayhem, and bad luck. The popular myth is that the day is unlucky because there were 13 people at dinner the night Jesus was arrested (the 13th being Judas Iscariot), and the next day, when he was crucified, was a Friday. Of course, if the date was according to the Jewish calendar, both events would have occurred on the 13th of the month.

Ah, but there’s the rub. As Christians tell the tale, the day these events took place had to have been erev Pesach, which would make it the 14th of Nisan, not the 13th. The Christians, for their part, insist that the dinner was a seder, which would make the day the 15th, but that would mean that a Jewish court met on a festival day; Jewish courts never met on a chag.

Considering that palms are prominent in the story and the dinner party took place on a roof, which is where sukkot were erected in ancient Jerusalem (and even in modern Jerusalem in some densely populated neighborhoods), it is more than likely that the events, if they occurred at all, took place during Sukkot. That, however, offers no solace to the Friday the 13th crowd, because Sukkot also begins on the 15th, in this case in Tishrei.

Then again, the Friday and the 13 may be separate "bad luck" items that, when combined, form an even worse day. In this scenario, the Friday is the day of the crucifixion and the 13 is the number of guests at that final and fateful dinner.

Triskaidekaphobia (fear of things 13) actually predates Christianity. Its origin may reside in Norse myth. In that version, it is top god Odin who hosts the dinner party and the 13th guest is Loki, the god of dirty tricks. Odin had an Adonis of a son, Baldir by name, virtually invincible by decree. Odin also had a blind son named Hod. Loki tricked the blind brother into hurling a sprig of mistletoe at the beautiful brother, instantly killing him (yes, mistletoe; it was Baldir’s kryptonite). Because of Loki’s fatal deceit, 13 took on bad connotations.

Friday, by the way, is a lucky day in Norse mythology.

Regardless of where the Friday the 13th myth originated, its roots are heretical. For Jews, both Friday and 13 are good, not bad. Among other things, humans were created on Friday and Friday is erev Shabbat. Thirteen is the age of mitzvot for boys; God has 13 attributes of mercy; and so on.

Another superstition that is all too common among Jews as well as the rest of society is the custom of knocking on wood for good luck, or to avert the evil eye. "I’m feeling better, knock on wood," people would say, rapping their knuckles on something made of wood as they say it.

Wood, however, has no magical powers on its own. One message of the monotheistic religions is that things made of wood are merely things made of wood; there is nothing god-like or mystical about them. So how can knocking on wood be of any benefit? Well, it depends on what the wood is supposed to symbolize. You see, it is not just any wood that gives you good luck; it is the wood of the cross used to crucify Jesus. To knock on wood is to symbolically reach out to touch Jesus’s cross in search of its blessings.

Judaism has its own superstitions. For example, many people wore things white, such as a kittel, on the just-passed High Holy Days. That is because the High Priest’s Yom Kippur robe was white, and we seek to memorialize that. The kittel is also used in burials. Supposedly, white is favored as a symbol of purity, but it is more likely because white in ancient times was seen as warding off evil spirits.

That is also probably why, at many of our weddings, brides wear white and grooms don a kittel. For added protection, it is also customary in many circles to accompany both bride and groom with candles; demons lurk in the dark.

The phrase "beli ayin hara," without the evil eye, is a popular one among many Jews; they automatically insert it whenever they talk about things that have not yet happened. Some people follow it by the East European Jewish equivalent of knocking on wood: spitting three times onto your ring and middle finger and saying "poo poo poo."

Sound is believed to ward off demons, too. That may be one reason we blow the shofar once a day for the entire month of Elul (except on Shabbat): We want to keep the evil spirits away so they do not interfere with our ability to repent. (So, too, we do not bless the new month of Tishrei, as we do all the other months, at least according to one popular reason: We do not want to give the spirits advance notice of the coming of Rosh HaShanah. It seems they cannot read a calendar.)

The custom of tashlikh also had its origins in pagan superstition. On the new year, pagans would go to the nearest waterway and toss in gifts to the gods lurking there to buy their goodwill for the coming year. This is why it took until the 15th century before any direct reference to tashlikh can be found in a rabbinic literature — and the first rule set forth in that text was a prohibition against throwing anything into the water.

A kabbalistic custom is to shake one’s clothes off during tashlikh, which harks back to a pagan custom of shaking off the demons.

The point is, we already have enough of our own superstitions; we do not also need to hide under the covers on Friday the 13th or knock on wood.