The Mesoamerican Long Count, which counted days (not years) went back to 3114 BCE: Mesoamerican Long Count calendar - Wikipedia
To add to your collection of ancient calendars.
No, it really isn’t. Luke didn’t just get the date wrong, he got the whole concept wrong. There is absolutely no possibility that everyone in the Roman Empire had to drop whatever he was doing and make a journey, possibly thousands of miles long, to the town where his ancestors lived 1000 years before, in order to pay his tax. If I am taxing you, I will go to your farm and count your livestock; I won’t have you travel from Spain to Alexandria and make your declaration to someone who has no way to check your figures.
As mocked in the play and movie Inherit the Wind, incidentally.
The winner of the Sidewise Award for Alternate History writing gets a plaque that refers to several historic dating systems - AD, HY, CF, AH (?), AUC, and EK:
Google Images failed me in trying to find a clearer picture of the plaque.
Although if she was born without original sin, she wouldn’t have felt any pain. I’d make that trade-off.
Ah! So anything in the last 45 years could be dated according to the Superbowl. They even number them using Roman numerals, to make them look important. If length makes it look more important, then the most important one so far is SB XXXVIII.
It’s no less genuine than the receipt I have for the Last Brunch, which was sold to me by an Italian priest. He explained that the date on it – 33 A.D. – was proof that it was genuine. 
kenobi 65:
Does it come with a piece of the True Hot Cross Bun?
Anno Hegirae or After Hegira.
The Muslim calendar, from the date that Mohammed led his followers from Mecca to Yathrib/Medina to escape persecution.
Hegira is alternatively spelled Hijra, Hijrat, or Hijrah.
There are a number of historic and cultural calendars available at www.calendarzone.com/ .
The above post leads to another way we know about chronology. If someone mentions the equinox or the solstice then we know the time of the year it occured (prrsuming they are far enough from the equator to be meanigful).
Astronomical observations are even more useful as they can date an event presicely (to literally the hour even) and with luck even get you to the general location of the event. We know the exact day of certain events because writers mentioned some astronomical events occuring at the time. We know quite a lot about the dates Battle of Arebela for instance, Babylonian chroniclers left quite a lot of infomation. We know the exact date of when some other event took place as there was an eclipse that day.
On the other hand astronomical data can be used to cast doubt on traditional tales. The Persian invasions of Xerxes took place traditionally during 480-479 BC. Herodotus mentions a solar eclipse, yet there was not one that was visible during those two year…there was one in 478 BC.
And just to confuse matters - the whole Julian vs. Gregorian confuses even modern calendars. The protestant countries took their time adapting to the popish calendar, which required dropping 11 days.
Plus, for a while April 1st was considered the start of the new year (still is for some accountants). You can find very old grave markers, I recall one for an infant in a church in England that said something like “b. Nov 1669, d. Feb 1669”.
there’s no trivia like calendar trivia.
My dad has a fancy chess set my grandfather gave him; the letter with it says something like “Aug. 26, 5th year of George V” so using years of a reign was a not completely uncommon ‘pretentious’ counting method even in the west."
Standard time: another Canadian invention!
Also, another important use for knowing the exact time of day was to find your longitude at sea. Latitude was easy to determine, but longitude was a much bigger challenge (to the point where “finding the longitude” was an expression of impossibility like “squaring the circle”), which is troublesome when one wishes to avoid crashing into shoals and whatnot. One simple method would have been to just compare the local noon (zenith of the sun) where you are to the local noon wherever you set out, except that there were no practical chronometers precise enough for the purpose and capable of staying in working order over a sea voyage until John Harrison built one in 1759.
To this day, bills and acts of the Canadian Parliament are dated (in addition to the Gregorian date) by the regnal year, e.g. 61 ELIZABETH II.
You try to pull off being born 4-6 years before yourself! It quickly becomes clear that only a deity can manage that feat. 
I’ve heard of a more modernized version of this in which January 1, 4004 B. C. is considered to be day 1 and counting up from there. Is this true?
Look at the link I gave. Ussher decided that the world began at 9 PM (or maybe 6 PM) on October 22, 4004 B.C. So if someone believes that the world began at midnight on January 1, 4004 B.C., they’re ignoring part of what Ussher wrote.
Yeah, as biblical errors go, Luke 2:1 is pretty easy to fanwank - all Luke does is contradict historical records. If I wanted to argue with a inerrancy believer, I’d rather throw some hardballs, like “which did God create first, trees or people?” or “what were Jesus’ last words?” - passages where the Bible contradicts itself.
Luke contradicts Matthew as much as any critic could desire. The genealogy he gives for Jesus is so different from Matthew’s that apologists claim that Luke is giving Mary’s genealogy, even though Luke explicitly says he is tracing through Joseph.
There are also glaring contradictions in the birth narratives. Matthew 2 says that Herod was so jealous of a possible infant rival that he ordered the slaughter of every male infant in the region of Bethlehem, and that Joseph was warned of this by an angel, fled to Egypt, remained there until Herod died, and even then was afraid to return to Bethlehem (Matthew gives no indication that Joseph had ever lived anywhere else before then, and mentions no census) while Archelaus (Herod’s son) ruled Judea, so he instead moved to Nazareth. Archelaus reigned for ten years after Herod died, so Joseph presumably did not visit Jerusalem for at least that long.
Luke 2 says that Joseph lived in Nazareth, and was just visiting Bethlehem for the ridiculous census requirement. Six weeks after Jesus was born (Mary’s time of purification), he took him to Jerusalem and publicly presented him in the Temple. And if doing that right under Herod’s nose wasn’t enough, there were various holy people in the Temple who proclaimed the infant Jesus as the long-awaited Messiah. Herod took no notice, and Joseph and his family returned to Nazareth unmolested, and returned to Jerusalem every year after that for the Passover.
Matthew never heard of the census, the full inn, the manger, or the heavenly choir singing to the shepherds. Luke never heard of the Star, the Magi (who were led by the Star directly to Joseph’s house, not a stable — but only after the Star got lost, and the Magi had to ask for directions at Herod’s court), or the Slaughter of the Innocents.
There is no way to reconcile the two accounts.
Maybe a discussion of biblical inerrancy belongs in another thread in another forum?