Apocalypse Day Planner

Heaven and earth shall pass away: but my words shall not pass away. But of that day or that hour knoweth no one, not even the angels in heaven, neither the Son, but the Father. Take ye heed, watch and pray: for ye know not when the time is.

—Mark 13:31-33 (American Standard translation)

Despite what the above quote says, writers are fond of putting precise dates on the Apocalypse. There's really nothing more dramatic than The End of the World as We Know It, but claiming that it will occur just Twenty Minutes Into the Future isn't quite as dramatic as saying it will occur in precisely Six Years, Eight Months, Seven Days ... and counting.

So one might propose that if all the movies, Video Games and other media depicting the world's destruction were correct, we'd be seeing the world ending at least once a week, and especially on dates that appear numerically significant.

Related to I Want My Jetpack (though in all seriousness, sometimes not even villains want their Earthshattering Kaboom).

No relation to The World Is Always Doomed, where the end of the world really is threatening to occur repeatedly.

For more information on fictional world history, see The Movie Timeline.

WARNING! There are unmarked Spoilers ahead. Beware. You've been warned!

The Earth has already been destroyed on

Circa 150,000 BC: the reimagined Battlestar Galactica - Robot War (different "Earth")
1911: Doctor Who - desolated by the godlike Osirian Sutekh in an alternate timeline and in orbit around a dead sun. (If you want to be technical, it could have been anywhere between 1911 and 1980)
18 Aug 1951: The Sarah Jane Adventures - The Trickster manifesting himself through a weak point in spacetime in an alternate timeline.
1963: The Doctor Who adventure game City of the Daleks - desolated by the Daleks in an alternate timeline with all of humanity bar Amy Pond wiped out.
1964: Dr. Strangelove - Slim Pickins slammed a nuke into the earth, triggering a nuclear war.
198-: Life The Universe And Everything - Earth Mk. 1 is destroyed by Vogons to make way for a hyperspace bypass.
1983: Conquest of the Planet of the Apes (though it's just all cats and dogs)
Feb 1985: Crimes of the Future (though it's just all women from age 12 to up)
22 Nov 1987: Buck Rogers in the 25th Century - Earth is devastated by nuclear war.
199X: Nuclear war turns the world into a Desert Punk wasteland prior to the events of Fist of the North Star.
Dec 1992: Battle of the Planet of the Apes - Nuclear war caused by apes.
1994: Thundarr the Barbarian - A rogue planet passed between the earth and the moon.
1996-1997: A plague swept the Earth in 12 Monkeys.
29 Aug 1997: Terminator - Nuclear war initiated by Skynet
1 Oct 1997: Crystalis
4 Feb 1998: Dexter's Labratory - Asteroids destroy the Earth.
5 Jul 1998: The Church Of The Subgenius. Any discrepancy with the current non-apocalyptic state of the world is due to it not being 1998 yet.
1999: X 1999
21 July 1999: Seikimatsu Occult Gakuin
9/9/99: Queen Millennia (although it was avoided)
Heavily implied to be 13-19 Aug 1999: Maya Amano is killed and Nyarlathotep destroys Earth in Persona 2: Innocent Sin.
13 Sep 1999: Space: 1999: Earth isn't actually destroyed but the loss of the moon causes massive earthquakes and volcanic eruptions.
01 Jan 2000: Too many to list. Just go over to the Millennium Bug page.
13 Sep 2000: Neon Genesis Evangelion. Actually, on second thought, not destroyed, just devastated.
03 Jan to 6 May 2001: Battletanx: Nuclear war initiated by men after a plague kills 99.9 percent of women.
7 Jul 2002: Y: The Last Man (for a good half of us.)
25 May 2004: UFO: After Blank
24 Jul 2004: Terminator 3 - Nuclear war initiated by Skynet. Just a bit late.
24 Dec 2005: .hack (though it's just all the computers).
7 Jul 2007: Haruhi Suzumiya destroyed the original universe and made it into something more interesting. Or she might have created it from scratch. It's not known for certain. The exact date is not known either, but 7/7/7 seems likely for a number of reasons.
7 Aug 2007: Odyssey 5 - The crew of Odyssey 5 witnesses Earthshattering Kaboom; is sent back in time to Set Right What Once Went Wrong.
24 April 2008 (minus.) (You knew it was inevitable.)
10 Sep 2008: The Earth Advisory Board.
April 13, 2009: Homestuck. All life on Earth is wiped out by meteor strikes. Centuries later, Earth is recolonized by the Exiles.
May 2009: Supernatural. All of the seals were broken and Lucifer walked free, which allowed the demons to take over the world.
19 Oct 2009: Knowing. A super solar flare burst from the sun, destroyed the ozone layer and engulfed the world in flames. Those who weren't killed in the fire died from radiation that punctured a mile into the planet's crust.
200X: Half-Life. The Resonance Cascade happens and thousands of aliens from Xen teleport onto Earth and portal storms ravage the planet. This later attracts the Combine who enslave what is left of humanity. By the of Half-Life 2 nearly all native wildlife has been destroyed, most of humanity dead and a sizable Zombie Apocalypse occuring.
20XX: Power Rangers RPM. Destruction of 90% of population and 100% of biosphere of an alternate Earth by a sentient computer virus, probably using nuclear-carpet bombing. Exact date unknown, but given the series' custom of taking place roughly when it was aired, 2008 is likely (it was aired in 2009, and the destruction happened a year into the backstory).
2010: The alien Zentran forces obliterate much of the Earth's surface in Super Dimension Fortress Macross.
5 Mar 2010: The Fall, in Persona 3's bad ending. (Approximate date - might be a bit later)
26 June 2010: The TARDIS explodes in Doctor Who, retroactively wiping out all of reality... Though technically we were being destroyed at the beginning of time, which slowly began to erase the future too it was just the TARDIS exploded on this date so... urgh. Wibbly Wobbly Timey Wimey... stuff.
21 April 2011: The Sarah Connor Chronicles - Yet ANOTHER Skynet-initiated Nuclear War.
2011: An asteroid hits the Earth, rendering it a wasteland almost as uninhabitable as planet Mars. (Remnants)
21 Dec 2012: According to The X-Files anyway. See also the Mayan Calendar example under "Real Life".
- Not just on The X-Files, but KIKEN too believes that the Earth will suffer the same fate on this date.
- And the movie Two Thousand Twelve.
- Date of the invasion in Universe At War
2013 Metro 2033 - The world is nuked to pieces.
1 Jan 2016: Neon Genesis Evangelion (Again. Sort of. Maybe.)
14 Feb 2016: Ghostbusters 2. At least according to Peter Venkman's talk-show guest. As Venkman puts it: "Valentine's day. Bummer."
12 Dec 2016: "The End", according to Dyson Frost's multiple flashforwards in FlashForward. Every timeline he's seen apparently ends on this date, implying that he at least believes an unspecified world-ending event will occur.

The Earth is still scheduled or predicted to be destroyed on

202X: Shin Megami Tensei - The remains of the post-nuclear, demon-ridden Earth are covered by a great flood.
23 Aug 2029: Rage - Earth is hit by the Apophis asteroid.
2040: X-COM: Terror From the Deep
2041: Barkley, Shut Up and Jam: Gaiden Due to the Chaos Dunk (not entirely destroyed, however)
2060: Sid Meier's Alpha Centauri
23 Oct 2077: Fallout series: A nuclear apocalypse resulting in all manner of mutant creatures which prey on the survivors.
2110: WALL-E: The Earth is abandoned by humanity due to the mountains of garbage making it temporarily too toxic to support organic life.
2150: Earth 2150: Earth is destroyed after an escalating war caused the Eurasian Dynasty to detonate experimental nuclear weapons on the North Pole, resulting in Earth being pushed out of orbit and spiralling into the sun. Whether you are an ED or LC soldier, or UCS robot doesn't matter: if you don't get off Earth using your side's evacuation fleet, prepare to get fried, melted, and finally burned.
2186: Earth is ground zero for this cycle's Reaper invasion of the galaxy. Only Commander Shepard stands any chance of stopping them.
2188: the "Starcrash" of Star Pirates occurs as a result of two asteroids being accidentally flung by gravity casters into Earth. Complete and total destruction of Earth, leaving it as only a debris field between Venus and Mars.
2517 (Several Generations Before?): Firefly (or possibly the Earth just ran dangerously low of resources... the shadow puppet seems to think something happened).
Jul 14, 9:38 PM, 2520: The Stone-Like is unearthed and proceeds to wipe out all life on Earth in a brilliant flash of light.
29th Century: Doctor Who: Earth is left lifeless for several millennia by solar flares.
2993 (give or take a few or several years) - Earth is plunged into eternal winter, waiting for Eternal Sailor Moon to rise and save it, found Crystal Tokyo and become Neo-Queen Serenity.
3028: Titan A.E.: Alien energy beings spin the Earth until it splits apart.
3700: IsaacAsimov's Robot and Foundation series: Irradiation of the Earth begins.
5 Jul 8661: Alternate date for X-Day, according to some members of the Church of the Subgenius (the original date apparently being read upside down).
circa 40000: Warhammer 40,000. The relentless tides of aliens, mutants and heretics begin to overwhelm the Imperium of Man, leading to the eventual destruction of Terra (or maybe not).
1002261: Babylon 5 (but we should be okay).
5 billion years from 2005: Doctor Who. The Sun will expand and devour Earth.
- This is only the final destruction of Earth in Doctor Who. Previously it will have been rendered uninhabitable due to solar flares. Probably twice.
500 AF (After Fall): Final Fantasy XIII-2. The goddess Etro dies, causing the land of the dead Valhalla to devour the entire world.

People in Real Life think the Earth has been/will be destroyed on

Somewhere between 30 - 100AD: early Christians believed that the end of the world would happen within their lifetime, due to a "cryptic" statement from Jesus that his followers would "not taste death" before the second coming of Christ.
1033 AD Many Christians of the time believed that Christ would come 1000 years after his death (even though this is probably not even the right year for that).
21 Mar 1843: Millerite Christians believed the world would end this date. Later amended to 21 Mar 1844, 18 Apr 1844 and 22 Oct 1844. See The Great Disappointment.
1914: Jehovah's Witnesses think the world started ending this year.
October 14–28, 1962: The period of the Cuban Missile Crisis, which people believed was the start of World War III, and as such, the beginning of the end of humanity as they knew it.
September 6, 1994: Some Christians predicted this was the date, but after it came and went it was changed to May 21, 2011. See Below.
August 11, 1999, as predicted by Nostradamus
01 Jan 2000: Experts predicted anything from mild inconvenience to the collapse of society as the Y 2 K bug (allegedly) crippled computers worldwide by confusing the year 1900 with the year 2000. This was also a popular day for apocalyptic cults to think the world would end.
May 5, 2000: According to the 1994 telecast of Ancient Prophecies, the Great Pyramid predicted the end of the world on this date.
- A book called 5/5/2000 Ice: The Ultimate Disaster predicted that an alignment of 5 planets would cause worldwide catastrophe.
06 Jun 2006: Also a popular date for cults to think the world would end.
January 19–20, 2008: A small group of people on the GameFAQs' Paranormal/Conspiracy Board believed that a giant meteor was going to destroy Earth on either the 19th or 20th. Considering the source it's not all too surprising that we lived to see the 21st.
May 21, 2011: According to the surprisingly large "Family Radio" organization of Christians, this date is when the world ends...
- ... Then when it got Jossed, the head of "Family Radio" hand waved that it was actually October 21, 2011 that would be the end of the world.
  - Jossed again; don't know what they're going to say now.
21 Dec 2012: The Mayan calendar ends, and some believe the world will end, even if the Mayans themselves didn't.
- And of course, the Mayans didn't. The calendar event coming in 2012 has happened several times throughout history. It's rare, but it's more like what the beginning of the millennium was to us than the end of their calendar.
2028 Potential impact by the asteroid Apophis.
2036 If Apophis misses, this is when it swings around for a second shot.
19 Jan 2038: Experts predict anything from mild inconvenience to the collapse of society as Y 2 K's big brother steps in and resets all clocks based on 32-bit UNIX timestamps to -2147483648 (which corresponds to December 13, 1901)).
in 100,000 years: When the next ice age is supposed to arrive at its earliest, once anthropogenic global warming finally wears out.
in 1 billion years: Temperatures on Earth become too hot to support life.
in 5 billion years: When the Sun is expected to turn into a red giant, possibly engulfing Earth in the process, before finally becoming a white dwarf and fading away.

May Happen At Any Moment

Left Behind tells us the rapture will happen "tomorrow" and it's pretty much all downhill from there for a good seven years, but as we all know, tomorrow never comes!
Australia, at least according to Mad Max will be taken out "A Few Years From Now."
Azathoth could destroy the world at any moment, and wouldn't even notice. Bummer.
A Supervolcano blows up, most likely in Yellowstone. Best case scenario would be the destruction of most of western North America. That's the best case scenario.
- Worst case scenario? The whole world dies from volcanic ash. Ouch.
Despite the introduction of nuclear weapons non-proliferation treaties (say that five times fast), enough live/active nuclear weapons still exist to wipe out the entire human race, depending on when they're dropped. We just can't take them apart as fast as we made them.
A massive solar storm hits us with a huge mass of charged particles, which interact with the Earth's magnetic field, sending huge currents along high voltage power cables, saturating transformer cores and melting them... all across the globe. The last time this happened - the Carrington Event in 1859 - the entire telegraph system in Europe and North America was taken offline. We're even more dependent on telecommunications now. Repairs could take months, during which access to food and water becomes a problem since so much of the developed world's infrastructure depends on electricity. The USA and Canada might even become third-world countries. And that's assuming it doesn't take out Earth's radiation belts (generated by our magnetic field) that protect us from the more harmful types of solar energy like the UV band that the ozone layer can't protect us from (sunblock claims to protect from UVA and UVB, well this band is UVC and the ozone won't stop it. The only thing protecting us from it is our planetary magnetic field).

May ALREADY have happened

Scientists trying to discover what 'time' actually is, have come up with a number of theories, one of which is that at any moment time could just stop, and the entire universe will be stuck in one final moment for eternity.

I Remember When All This Will Be Again.