Magic doesn't obey human-made timepieces, but follows the cycles of nature and the movement of the spheres. A spell's duration, then, extends from sunrise to sunset, or during a phase in the lunar cycle, or some other vaguely fairytale measurement of time such as one's Dangerous 16th Birthday or A Year and a Day or by following a celestial zodiac.
Comes in two varieties
- Magic Has Dramatic Units of Time: Sunrise, sunset, twelfth gong of the clock-tower, the phases of the moon, birthdays, saint's days, Sabbath, etc. Which invokes all kinds of Fridge Logic, such as, what would use something so inaccurate as when the sun sets, especially since the world is round and there's always a sunset somewhere?
- Magic Has Its Rules: Somehow setting limits such as a "Rule of Three" or "Until the Castle Rises Above the Clouds" or "Until the Sun Sets," or "This spell/ritual/technique can only be performed by a virgin" makes the power work better or at all. So whatever happens needs to happen within the rules instead of at one's convenience. If a rules lawyer is around, this sometimes leads to No Man of Woman Born.
- Inuyasha has a instance of being a human when the new moon comes around.
- Placing restrictions on Nen powers in Hunter × Hunter can act as a power multiplier for an ability, depending on the restriction.
- In Nanatsuiro Drops, Tsuwabuki turns into a sheep plushie after sunset and changes back after sunrise. However, when the moon is full, he stays a plushie for a whole day, and during a new moon he stays human all day.
- Angels and Demons who have not been fully trained in all magics in the manga Wish follow cycles. Angels are adult form during the day and chibi form during the night and demons are vice versa.
- In Digimon Adventure, it was said that when the clock struck the Hour Of The Beast (i.e six seconds after 6:06 PM), the undead Digimon king would reveal his true form as a beast (i.e Myotismon being reborn as VenomMyotismon).
- In Fushigi Yuugi, each of The Four Gods can only be summoned when all of their Seishi are found, and the priestess must be a virgin. However, there is a certain failsafe: if, for example, a Seishi is missing/dead/incapacitated/an imposter, or the priestess is only a Technical Virgin (or not a virgin at all, or believes herself not to be), the Summoning Ceremony can still be performed. The priestess and her Seishi will just have to retrieve a MacGuffin called the Shinzaho, which is an artifact left by the last priestess to enter the book. (This artifact can be literally anything, so long as it has some personal connection to her: a piece of jewelry or clothing the previous priestess wore, an accessory she carried, even her Kid from the Future.)
- In Beauty and the Beast, the Beast had to learn to love another and earn her love in return before the last petal on the enchanted rose fell off in order to break his curse. Fortunately, this also undid his apparent death.
- Brave: Elinor's bear transformation will become permanent by the second sunrise if Merida doesn't undo it until then.
- Coco: Miguel will be forced to remain in the Land of the Dead forever if he doesn't get home before sunrise the following day.
- The Little Mermaid (1989): The contract is made until the sunset on the third day. Covering sunsets and the rule of three.
- While not quite magical, in Once Upon a Forest, the heroes have only until "the moon is full" to collect the herbs and return them to save their friend Michelle. In this case, it might not have been so much the Moon itself as it was an approximation of how much time they had before Michelle's illness reached a point where it would be incurable.
- Shrek is big on this. In ''the first film, sunrise and sunset were important times for Fiona. In the second, Shrek has until midnight to make the effects of his potion permanent. Lampshaded:
Shrek: Why is it always midnight?
- ParaNorman: Norman is supposed to read from the book at the witch's grave before sunset. When he finds the apparent spot, it doesn't work and the curse takes effect, but that's because he was at the Puritans' burial site, not the witch's.
- 16 Wishes: Abby's candles that make her sixteen birthday wishes come true won't work anymore after midnight and all granted wishes will become permanent.
- The Boy Who Cried Werewolf: Jordan's werewolf transformations at night will become permanent by the next sunrise if she isn't cured by then.
- In The Dark Crystal we have the Great Conjunction, an alignment of the world's three suns, described as a catalyst for "great change." In the film, the Dark Crystal must be completely reassembled and the Mystics and Skeksis reunited by the upcoming Great Conjunction in order for harmony to be restored.
- Mogwai shall not be fed "after midnight", lest they turn into Gremlins. Nothing is said about when you can feed them again. In fact, a lot of people make jokes about this rule when the heroes try to warn them about the gremlins. (The one about "if he's eating on an airplane, and passes through a time zone" is probably the most complex. They actually raise a valid point: the rule is kind of vague.)
- In the silent film The Golem, the Rabbi can only create the Golem while a certain astronomical constellation occurs. The occurence of another constellation supposedly causes the Golem to rebel.
- Ladyhawke: A couple is cursed so that she's a hawk by day and human by night, and he is human by day and a wolf by night. They only get to see each other in the moments of sunrise and sunset, until they are saved by Rules Lawyering.
- In the vampire movie Once Bitten, the lovely female vampire must have blood from 3 virgin males before Halloween each year to retain her youthful appearance. Although she does drink non-virgin blood, this merely sustains her, not her looks.
- The Santa Clause 2: Scott Calvin has until midnight on Christmas Eve to find someone worthy to be his Mrs. Clause and get married to her, or he'll stop being Santa forever.
- In Soultaker, the heroes have until their life support is turned off at midnight to reunite with their bodies. And then the movie more or less completely ignores said deadline.
- In Tiny Christmas, Elfonzo's shrinking goggles lose their powers when the sun rises on Christmas Day.
- In Your Highness, the evil wizard needs to perform a certain ritual with a virgin to create a dragon. This ritual may only be performed once every 100 years when the two moons align.
- The Dresden Files:
- Sunrise acts as a magical Reset Button. Many but the most powerful spells either fade completely or weaken considerably when the sun rises.
- Faerie magic likewise has this limitation. In Changes, Harry gets a whole panoply of goods from his faerie godmother, the Leanansidhe, but learns that they're only good until noon the next day. She implies that, had the gift come from a Summer faerie rather than a Winter one, it would indeed run out at midnight like Harry was worried might happen. He's worried because the villain's spell is also keyed to midnight, and he's got quite enough on his mind as it is.
- Also, any ghosts or spirits which try to go out during the daylight will be destroyed, unless they are inside a specially constructed multi-dimensional "house" (Bob's is a skull) or otherwise hidden from the sunlight.
- And, in Cold Days, Harry finds out that Halloween night is a time when even immortals can be killed.
- Similarly, in the October Daye series, a number of spells dissipate at sunrise. But it doesn't last until sunrise. It lasts until the first birdsong is sung.
- In Discworld, according to Death, The lawyers of Fate require a loophole. when dealing with prophecies.
- Similarly, in A Game of Universe, the contract with the devil has a loophole: One year before it runs out, 13 heroes can be recruited to find the holy grail. If they find it before the contract runs out, the contract is nullified.
- In Robert E. Howard's Conan the Barbarian story The People of the Black Circle, the king is killed by magic on a certain date.
- In Robert E. Howard's Kull / Bran Mak Morn story "Kings of the Night", Kull's appearance is governed by this.
Out of the sunrise he came—into the sunset he has gone. Out of the mists of the ages he came to us, and back into the mists of the eons has he returned—to his own kingdom
- In Adrian Tchaikovsky's Dragonfly Falling, Uctebri explains he is awaiting the most auspicious date.
- In L. Jagi Lamplighter's Prospero Lost, Theo recommends that if they can't wait for a holiday, to use the Ouiji board on Wednesday. (Odin, and Hermes, the two gods associated with that day, were both associated with magic.)
- In Edgar Rice Burroughs's The Monster Men, Chinese medicine is described as using this.
- In Wen Spencer's Tinker, Windwolf explains that times are important for spells — blessings are best at noon, curses on moonless nights.
- In Living Alone by Stella Benson, Richard describes a spell cast at low tide, Christmas night.
- In The Shattered Kingdoms, Meiran's magical illness, which was caused by being "blessed" by both a sun god and a moon goddess when it should have been just one of them, has a debilitating effect on her at dawn and dusk.
- In season six, the antagonists' plan to open Purgatory and harvest the Soul Power within hinges on a ritual that can only be performed during a lunar eclipse.
- In season seven, the attempt to reverse the results of said ritual, i.e. return all the souls to Purgatory must also be done during a lunar eclipse. Except there isn't going to be one anytime soon. So Death says he'll make another.
- Changeling: The Lost: if you're lucky, contracts work until sunup or sundown, whichever happens first; or for free if you invoke Food Chains.
- also Pledges, Tokens, Goblins, and the True Fae.
- Vampire: The Masquerade and Vampire: The Requiem both have a few powers, usually Blood Magic, that end at sunrise.
- Dungeons & Dragons, around late 1st/early 2nd edition, would often include powers, usually magic items, that could be used "X times per day", but didn't define what the device considered "a day" (e.g., sunset, sunrise, 24 hours from the last use, etc.). This language was clarified in later editions.
- In In Nomine, different kinds of beings get a bit of spent Essence back at different times of day at least when they are on Earth. Angels get theirs at sunrise, humans get it at noon, demons at sunset, and ethereal spirits at midnight.
- A Midsummer Night's Dream: The fairies show up When the Clock Strikes Twelve.
Puck: Now it is the time of night
That the graves all gaping wide,
Every one lets forth his sprite,
In the church-way paths to glide:
And we fairies, that do run
By the triple Hecate's team,
From the presence of the sun,
Following darkness like a dream,
Now are frolic:
- In Ghost Trick, the ghost Sissel is told that he will vanish from this world at dawn. It turns out that this is a lie to motivate him.
- In Spirits Of Anglerwood Forest, the Big Bad Ezra has turned people into trees and captured their spirits. When the sun rises on the Winter solstice, all the captured spirits will be lost forever.
- In Tales of the Questor, the hunt lasts until cockcrow. Not mind you, dawn. (Good thing for Exact Words.)
- In Wapsi Square, 2012 is not only When the Planets Align, it's when you can do something about it.
- In Dream Keepers Prelude, Namah deduces her show's on as if it were this.
- In Doodze, the sunlight only protects you as long as it's up.
- In Erstwhile, the woman is allowed to go home only overnight.
- In Dragon Mango, making the seal had drawn on the raw power of the stars' alignment.
- In Tales of Wyre, demons and some spells vary in power on a daily cycle: they are at their strongest (or sometimes weakest) when their associated star is overhead at some special location.
- In Killing Spree, a strange mystic gives the main character the power to do anything he wants, but only until midnight. Having been turned into a Nigh Invincible badass, he naturally goes on a mass murder spree. The deadline comes into play at the end of Killing Spree VI, when he's seeming shot dead by a vengeful cop, only for the mystic to reveal that Jase can't be dead because it's not yet midnight and the spell hasn't worn off yet.
- In Avatar: The Last Airbender, waterbenders draw their strength from the moon, so they're strongest during a full moon and weakest during a new moon. When Admiral Zhao kills the Moon Spirit, the moon vanishes and the waterbenders are left temporarily powerless. Firebenders, similarly, draw their power from the sun, so Sokka plans the Gaang's invasion of the Fire Nation to coincide with the Day of Black Sun, a solar eclipse during which the firebenders will be temporarily powerless, providing an excellent window of opportunity.
- On the flipside, Aang has to defeat Fire Lord Ozai and end the war before the 100-year arrival of Sozin's Comet, which would boost the firebenders' powers to such high levels that the war would essentially be over. They fail, but Aang manages to defeat Ozai anyway.
- In Book 2 of Legend of Korra, Unalaq's plan to open the Spirit Portals, free Vaatu and fuse with him, then use his power to destroy the world, all hinges on an event known as "Harmonic Convergence" that only happens once every few hundred years.
- Big City Greens: When a Green family member takes on the family's Rite of Passage, they have until the sun goes down to fight a tough animal, wrestle it, and pin it down for three seconds. If they fail to do this by then, they won't be a Green anymore and will have to change their last name to something else.
- Gargoyles They are stone during the day and flesh at night, in the pilot they are also cursed into dormancy "Until the Castle Rises Above the Clouds".
- Most magic in Gargoyles has similar limits. According to Word of God, adding any sort of "this spell goes away when X happens" condition, no matter how ridiculous it may sound, makes the spell much easier to cast successfully.
- And other spells are of the first (sun- or moon-based) variety: Demona's Depopulation Bomb in "Hunter's Moon," for example, only works on the night of the Hunter's Moon. Word of God is that Goliath and Xanatos seized it from her, waited a few nights, and destroyed it when the moon started waning. And her Stone at Night curse in "City of Stone" falls under both varieties: It is only effective at night (variety 1), and it is broken for good when and if "the sky burns" (variety 2).
- On Rocko's Modern Life, Filburt has an uncontrollable urge to go back to Kerplopitgoes Island on his 21st birthday, which coincides with the alignment of the planets.
- In the same episode, Heffer has an urge to go on a fast-food binge, prompted by the alignment of every fast-food joint in O-Town.
- In the Tuff Puppy Christmas Episode "A Doomed Christmas", if Santa doesn't start his yearly run by midnight on Christmas eve, his reindeer will lose their flying magic, and there will be no Christmas for that year.
- Vampirina: The episode "Vampire Weekend" has Vee and Poppy find full moon pendants which switch their lives on the day of a full moon. If they don't switch back before the full moon rises in the sky, they stay switched forever.
- On Winx Club, the first third of the fifth season follows the Winx on a quest to obtain the Sirenix transformation. However, this is a Timed Mission; they have one lunar cycle to finish it. If they don't earn Sirenix before the end of the day that the lunar cycle ends, they'll lose their powers forever.