By the calendar, Halloween is celebrated on Oct. 31 every year, and that date has significance - but not right out of the gate, holiday-wise.

Halloween History: A Timeline

In 609 A.D., Pope Boniface IV heralded the celebration of Christian martyrs when he declared "All Martyrs Day" on May 13, a celebration that endured for 200 years. Fast forward to the eighth century, when Pope Gregory III, the leader of the Christian world, mandated Nov. 1 as a date to celebrate not just all martyrs, but "all saints," too. Hence the term, "All Saints Day."

This date coincided with the Celtic new year, held also Nov. 1, where celebrants on the British Isles and Ireland would ring in the new year with a twist - lighting bonfires and singing chants that were meant to ward off any evil spirits that might cause harm to the populace.

There was a good reason for such precaution, based on the Celtic rituals at the time. Nov. 1 on the Celtic calendar represented the end of summer and the beginning of winter, a period of cold and darkness for mostly poverty-stricken citizens, who had to wait months before they could plant seeds and grow their harvest. That's where the infamous "black and orange" Halloween motif started, as well. Black was designated by the Celts as the color or winter and orange as celebrated as the color of summer - Halloween hues that remain legendary today.

The Celts also were big believers in the supernatural and marked the night before the new year as the official boundary between the living (the "new") and the dead ("the old.") The holiday was officially known as Samhain, when "celebrants" believed the dead would return to the land of the living and once again walk the earth.

As ethnic groups meshed in Great Britain and on the European continent, Halloween really took hold in the 19th and 20th centuries. Parties to celebrate the "undead", with revelers dressed in costumes and swapping ghost stories over a bonfire became commonplace on Oct. 31 every year.

In America, the holiday came over the Atlantic with the millions of European immigrants who traveled to America in search of a better life.

By the early 20th century, the idea of dressing up and visiting neighbors on Halloween for "trick or treats" was commonplace. As the American middle class rose in abundance, Halloween became an even bigger deal, as Hollywood contributed to the cause with fabled monster movies like "Frankenstein" and "Dracula", which spawned legions of little vampires and monsters parading around on Halloween nights in American neighborhoods - a practice that is still pervasive today.

Where Did the Name "Halloween" Come From?

Halloween, as a term, is widely viewed as originating in Scotland, in the early 1700s. "Halloween" is derived from the term "Holy Eve," the name of the day before the Nov. 1 Celtic new year.

Glasgow poet John Main cited the term "Hallow-E'en" in his poem of the same name in 1783, where it became immersed in the Celtic culture and was widely used among the populace to define the Oct. 31, pre-new year holiday.

Five Halloween Traditions Explained

Of course, with Halloween comes multiple holiday traditions - most of them of the spooky variety. Here's a glimpse at some of the most venerated Halloween traditions, and how they started.

1. Ghosts and Spirits

During the Celtic festival of Samhain, speculation had it that the dead walked the earth. That speculation took hold over the centuries as older family members told stories of the "undead" to wide-eyed children on chilly nights over a blazing fire. By the 20th century, it was customary for Halloween celebrants to dress up as ghosts to commemorate the holiday.

2. Jack-o-Lanterns

The term "Jack-o-Lanterns" stems from one of the greatest stories of Halloween lore. It originates from an old Irish take about "Stingy Jack" - a mythical legend who would repeatedly hunt and imprison the devil, and would only release Satan after he promised never to send Stingy Jack to Hell. While the devil held true to that pact, God didn't, as Stingy Jack was barred from entering heaven when he finally died. Doomed to straddle heaven and hell for eternity, Stingy Jack roamed the earth, aided by a huge chunk of burning coal (a gift from the devil) to light his weary way. And that's how the Jack-o-Lantern came about.

3. Dressing up for Halloween

The tradition of dressing up in Halloween costumes also dates back to Celtic legend, as All Hallows Eve celebrants concocted a novel tradition to disengage from ghosts and goblins haunting the earth. Instead of donning their everyday garb, they "hid" from evil spirits in costumes with the idea that the evil dead would mistake them for one of their own and leave them alone. The gambit seemed to work as centuries later, we still dress up for Halloween.

4. Trick or Treat and Candy-Gathering

Like most holidays, celebrants deem it okay to unbuckle their belts, overindulge and worry about any added pounds or stomachaches later on. So it goes with Halloween, where, once again, legend had it that those spirit-skittish Celts would leave potatoes, carrots and turnips, among other foodstuffs, outside their abodes to placate any wandering ghosts or goblins roaming the turf on All Hallows Eve. The idea caught on, but with something of a backlash - actual living people began dressing up as spirits to cash in on the free food and drink, and in the process, began solidifying the Halloween "trick-or-treat" celebration culture.

Watch: Top-Selling Candy for Halloween (click below)

5. Bobbing for Apples

The tie-in between Halloween and bobbing for apples has a seasonal bent to it, as juicy apples are a common fall foodstuff and widely available to holiday celebrants. This autumn tradition, though, dates back to ancient Rome, where the festival honoring Pomona, the goddess of abundance, was celebrated with the use of apples for courting purposes. Legend has it that young men and women would gather in a circle and take bites out of apples. Inside the apples were small slips of paper with a boy or girl's name on it. Once you bit the apple and pulled out a name, that signaled your mate for life. Over time, young lovers came to view apple pairings as a sign of marital bliss, and the practice of "bobbing for apples" grew exponentially.

Halloween in 2018

No doubt, Halloween remains on the big stage when it comes to mega-U.S. holidays. It's widely viewed as the gateway into the late-year triumvirate of mega-holidays, along with Thanksgiving and December holidays.

Data from the U.S National Retail Federation tells the tale. This year, buoyed by a roaring economy, total spending for Halloween should crest $9 billion, the second highest in the NRF's 14-year history of tracking Halloween spending in the U.S.

Here's how the NRF breaks down all of that Halloween spending:

U.S. consumers plan to spend . . .

  • $3.2 billion on costumes (purchased by 68% of Halloween shoppers)
  • $2.7 billion on decorations (74%)
  • $2.6 billion on candy (95%)
  • $400 million (believe it or not) on Halloween greeting cards (35%).

Year after year, Halloween has grown into one of the most popular U.S. holidays, one with none of the preparation angst of Thanksgiving and Christmas.

It's also one where you have the flexibility to celebrate Halloween dressed like Donald Trump and go hunting for Hershey Bars - or not. Apparently, millions of people will do some variation of that come Oct. 31.