Are you an ECommerce entrepreneur outside the United States who sometimes depends on working with Americans?
And who isn't these days?
Perhaps your virtual remote team includes a few staffs hired over UpWork?
And have you ever been mystified by the panoply of American holidays?
Then this post is for you. Because I'm in Iowa (it doesn't get any more American than that) and have worked with people all over the globe, and I'm always running into confusion as to which holidays are significant and which ones are a blow-off. I've had clients who offered me Groundhog Day off at one extreme, and clients who were shocked that I wasn't expecting to pull a sixteen-hour shift Thanksgiving Day at the other.
So bookmark this and save it for the year!
I will be rating the holidays from 1 to 5, "1" being "no big deal" to "5" being "everybody in the country is either at a big family banquet or getting sloppily toasted, so forget getting anything done until this blows over." All paid days off get at least a "2." Holidays which are subjective depending on the individual will be noted because the US is still a cultural melting pot no matter how many walls Trump builds.
Come on, keep up with me, this will be fun!
January 1: New Year's Day 
At least we start with one holiday familiar to the rest of the world. In the States, this is mostly a day to recover from New Year's Eve, where absolutely everybody stays up 'til midnight or tries to. By the day proper, not much is going on except a big cup of coffee and flopping on the couch to watch the Rose Parade in Pasadena (no, I don't know why the whole country cares about one city in California all of a sudden). We get the day off anyway.
Get ready for business, because hundreds of bleary-eyed Americans will be ready to go back to work January 2nd, with a huge debt to work off.
[nearest Monday to January 15-21]: Martin Luther King Day 
It's a paid day off for federal workers (postal service), and observances remark on the history of civil rights in America. MLK, Jr., was a respected civil rights leader. Not treated as an actual event.
February 2nd: Groundhog Day 
Nobody cares except some folks in Pennsylvania. It's a silly custom where a rodent predicts the weather. It gets one good Bill Murray movie, though. Groundhog Day is actually the vestigial remains of Candlemass, believe it or not, though not even devout Catholics have usually heard of it. Candlemass borrows from Imbolc, the Pagan-Gaelic custom of observing animal behavior for signs of the coming season's weather. So we come back from all that with… You know what, just watch the movie, it's very funny and it actually explains the holiday along the way. No, we don't time travel.
[first Sunday in February]: Superbowl Sunday [subjective]
For the vast majority of Americans, American football (AKA "handegg") is a religion, full stop, and this is its holiest day. Depending entirely upon their political alignment, Americans will either hold this as the most sacred day of the year or spit on it with contempt (MEEE!). You get hazed, harassed, bullied, and ostracized in America for not being fanatically stupid about football.
Observances include all-day fraternal parties, rampant sexism, and rioting for the team that didn't win, just like a rugby or soccer match in other countries. Local news stations will tailor the weather forecast in the preceding weeks to report the weather conditions over football stadiums and literally nowhere else.
February 14th: Valentine's Day 
It's an unofficial holiday for sweethearts and to make everybody who's single feel cold and miserably alone. Candy and a card, maybe dinner out if you're dating.
[third Monday in February]: President's Day 
The president is that dumb guy we put on TV to yell at other countries. George Washington was the first president and his birthday is February 22nd. Officially, it's a paid day off for federal workers. But for some reason, it's slowly morphing into a day of honoring all presidents, since the second-most honored president, Abraham Lincoln, was born February 12th. All that happens is that local businesses make a big fuss about having President's Day sales.
[sometime around February or March]: Mardi Gras [subjective]
Observed with a big blowout parade and festival in New Orleans, Louisiana , and virtually ignored everywhere else . Tied in with that whole weird Easter calendar thing, discussed later. It's got days like "Ash Wednesday" and "Fat Tuesday," so it drags on for a week or so. More popular in the rest of the world, apparently. Imported into the United States by French Catholic immigrants, so it's one of those cultural melting pot days. If anybody else observes it, it's an excuse to get drunk.
March 14th: St. Patrick's Day [subjective]
This is another import for the cultural melting pot, for Irish Catholics, who might throw a small parade or have a themed supper. Even to them, it's a  at best, for the rest of the country it's an excuse to drink green beer. There's a lot of these "excuse for drinking" days milling about.
[sometime around March or April, always Sunday]: Easter 
Easter is familiar to the rest of the world, but in the States it's a paid day off for those who wouldn't have Sunday off anyway and not much else. Big religious observers show the highest church attendance out of any day of the year, and make a feast day of it, with candy treats for the kids too. Everybody else mostly blows it off.
Americans are confused out of their minds by Easter. It's this weird Catholic thing whose date is calculated by the Illuminati in a secret ritual, and it imports more overtly Pagan roots than any other holiday save Christmas. Then you take America, which is mostly Protestant and has perverted Christianity into a Lovecraftian abomination that means the exact opposite of everything it originally meant, but then we emphasize the Pagan roots with the Easter Bunny, eggs, chicks, flowers, fertility symbols all over the place.
As a result, Easter-themed horror movies include Beaster Day: Here Comes Peter Cottonhell (2014), Easter Bunny Bloodbath (2010), Donnie Darko (2001), Bunnyman (2011), Night of the Lepus (1972), Kottentail (2007), and Easter Casket (2013), not counting, of course, the sequels.
April 1st: April Fool's Day 
Yeah, nobody does this. It's a holiday devoted to practical jokes on the Internet only, not that you can tell it apart from any other day on the Internet.
May 5th: Cinco De Mayo [subjective]
Latino cultural import, this started out as a Mexican military observance (Battle of Puebla, 1862), but has become something more of a racket in America than it was in Mexico, becoming just a general cultural celebration. Mexican-Americans have a parade and throw a party . Everybody else, you guessed it, uses it as an excuse to get drunk.
Mexico and America are right next to each other, after all. And despite how prejudiced parts of America seem to be, most of the country is pretty enthusiastic on Mexican culture or there wouldn't be a Mexican restaurant in every city.
[second Sunday in May]: Mother's Day 
Take your mom out to dinner or give her a phone call if you're far away. Not much else is made of this.
[last Monday in May]: Memorial Day 
Paid day off for most of the country. If you haven't heard it elsewhere, America outspends the rest of the world on military by a wide margin, so this is one of several somber military observances, this one honoring the dead. Marches and parades, military bands playing, lots of flowers and wreaths placed on graves, that sort of thing.
Get ready for another weird American notion: the civil religion, where America is idealized as God without the oversight of an organized dogma. That's how we get half-nationalist / half-religious orders like the Knights of Columbus, which weirdly is a Catholic group with $21 billion in assets including a $100 billion dollar life insurance business. And you thought the Pledge of Allegiance was creepy? Adding "under God" was the Knights of Columbus' idea.
[third Sunday in June]: Father's Day 
If you thought Mother's Day was underplayed, dad's lucky if he gets a phone call. Dads don't seem to mind much, possibly because the concept of a man hanging around to parent his offspring for the whole 18 years is such a foreign one to the US.
July 4th: Independence Day 
Just about any democratic nation, which has a past history otherwise, understands this concept. In America it's celebrated with fireworks, explosions, gunshots, more fireworks, trips to the emergency room to treat third-degree burns, drinking, outdoor feasts, and more fireworks. Paid day off for the whole country. Usually gets rolled together with the nearest weekend.
Even for those who aren't particularly patriotic, this day comes in the middle of Northern Hemisphere summer, when everybody has been working like a dog for a long time without a break, so nearly everybody takes the excuse to blow off some steam.
[first Monday in September]: Labor Day 
An almost resented event, it's a federal paid day off and nothing more. Most boring holiday ever. "Labor Day" smells too much like "Socialism (AKA Satan)" to most Americans, so you can almost get smacked just for bringing it up. A leftward political swing can get a few people observing it again.
[sometime around September-October for a few days]: Oktoberfest 
Cultural import from the German immigrants, which form a huge percentage of Americans. It started out as a Bavarian wedding feast in the 1800s, and then what the heck, it's a nice time to drink beer outside. In the States, you guessed it, it's beer time! Americans with German-leaning heritage will absolutely attend a big tent carnival and get sloshed.
It should also be noted that late-September / early-October in general seems to be a cultural festival season in the United States, particularly for anything tied to old-world Europe. If there's a Renaissance Faire, it's held around now. Small towns hold festivals around whatever their local agriculture produces. It's back-to-school after summer vacation for the kids, so school-themed events fire up.
[a Monday somewhere in early October]: Columbus Day 
Yeah, it's observed in elementary school only. Lately, as America slowly acknowledges that it was celebrating the beginning of the massacre of the indigenous people that used to live here, it's been played down or changed to "Indigenous Peoples' Day," go figure.
October 31st: Halloween 
Yes, we really do this! Halloween kicks off the official holiday season in the States; from here until New Years' is "the holidays." It's like a Gaelic-Pagan import converted into the celebration of everything scary. Horror movies, haunted houses, partying teenagers in cemeteries, parties everywhere. In some places, like the Midwest (MEEE!) it's divided into multiple days: "Beggar's Night," for the kids to go trick-r-treating (wearing costumes and getting candy from house visits at night), usually a day or two prior, and Halloween proper on the 31st, so the adults can party and not worry about running over little kids in costumes on the way home.
Now, this may seem a tenuous concept, but Halloween in recent years has morphed into having more meaning invested in it. So to speak, it is becoming "Liberal Christmas," while Republicans are more likely to ignore Halloween and start decorating for Christmas proper. This is somehow tied to The Rocky Horror Picture Show becoming the unofficial movie of the season. The costume aspect has led Halloween to become a celebration of being "different," "individual," or an outsider to mainstream American culture. LGBTQ people seem to celebrate it unanimously. From anime cosplayers to borderline deviants, it's become a holiday to "let your freak flag fly."
Regardless, even the least observant scrooge will feel compelled to hand out a bowl of cheap candy on trick-r-treat night. Oddly enough, it's not a paid day off for anyone and the federal government seems to hardly be aware it exists.
November 11th: Veteran's Day 
Here comes another American military holiday! This one's to honor the military service members who are living, although it's still an appreciation for every military member ever. Repeat Memorial Day, only fewer wreaths and more fireworks.
[fourth Thursday in November]: Thanksgiving 
This seems to be the holiday that baffles non-Americans the most. That's because it's one big whooping lie. We tell everybody it's a patriotic celebration of the original European settlers in America (pilgrims, the guys in the funny brown suits and black hats) surviving their first year in the New World colony without any of them starving.
But the truth is: It's a harvest-festival feast day. Have you noticed, most countries the Northern Hemisphere over have a feast day around this time of year? That's because the harvest season is over, winter's about to start, and it's getting colder. That's a great excuse to fire up the oven and warm up the house, pack on a few calories against the coming cold weather, and of course, have a bookend to the beginning of Christmas shopping season. Black Friday, the day after Thanksgiving, is the day capitalist consumerism decrees we stampede into stores and beat the snot out of each other in a frenzy of consumption.
Roll together that Thursday, the Friday, and the subsequent weekend. You can't get anything productive done. Nobody else is willing to work at all, except the retail clerks we're going to sacrifice to Mammon. Most everybody gets a whole paid long weekend off here. Forget it, just eat your turkey and wait for this to blow over.
December 25th: Christmas! [5!]
Obviously, Christmas needs no introduction on the international front. In America, blow out another week for wherever Christmas lands on the calendar, and since New Years' is just a week later, forget getting anything done from about December 20th to the end of year
Kids get two weeks off school, everybody gets a paid day off or they get visited by three ghosts that night, and no matter what religion you are, America just re-brands Christmas as Hanukkah, Kwanza, Yule, or a day for atheists to get drunk and open presents. You celebrate Christmas anyway if they have to hold a gun to your head. They actually celebrate Christmas in prison, that's how serious this is. Of course, it's just as overtly Pagan cultural appropriation as any other Christian holiday, but since the whole world does it that way to varying degrees, no need to go into that song and Krampus dance here.
January 31st: New Years' Eve 
Yep, just like the rest of the world, the US famously stays up til midnight watching the big ball drop in New York and of course, have a party. This is often known in bar culture as "amateur night," because even non-alcohol tea-teetotalers and 87-year-old widows will tiptoe out for a beer tonight. Tomorrow morning we get to drag ourselves out of bed and start the whole damn thing over again.
Speaking of damn things, this one's done!