->''"Even the arts you call sorcery are governed by cosmic laws," answered the man in the green turban. "The stars direct these actions, as in other affairs. Not even my masters can alter the stars. Not until the heavens were in the proper order could they perform this necromancy."''
-->-- '''Creator/RobertEHoward''', ''Literature/PeopleOfTheBlackCircle''

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 DangerousSixteenthBirthday or AYearAndADay or by following a celestial zodiac.

Comes in two varieties
# '''Magic Has Dramatic Units of Time''': Sunrise, sunset, [[WhenTheClockStrikesTwelve twelfth gong of the clock-tower]], the phases of the moon, birthdays, saint's days, Sabbath, etc. Which invokes all kinds of FridgeLogic, 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?
# '''[[FantasticFragility Magic Has Its Rules]]''': Somehow setting limits such as a "RuleOfThree" or "Until the Castle Rises Above the Clouds" or "Until the Sun Sets" makes the power work better or at all. [[MagicAIsMagicA 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 NoManOfWomanBorn.

If the events happen on their own after astronomical events, see WhenThePlanetsAlign. Not to be confused with CosmicDeadline.
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!!Examples:

[[foldercontrol]]

[[folder:Anime & Manga]]
* ''{{Inuyasha}}'' has a instance of being a human when the new moon comes around.
* Placing restrictions on Nen powers in ''Manga/HunterXHunter'' can act as a power multiplier for an ability, depending on the restriction.
* In ''VisualNovel/NanatsuiroDrops'', 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 ''Manga/{{Wish}}'' follow cycles. Angels are adult form during the day and chibi form during the night and demons are vice versa.
[[/folder]]

[[folder:Fairy Tales]]
* Literature/{{Bearskin}} must wear the bearskin for seven years.
* ''Cinderella'': The magic stops working at midnight.
[[/folder]]

[[folder:Film]]
* ''Film/{{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 then were saved by [[RulesLawyer Rules Lawyering]]
* In ''Film/YourMajesty'', the evil wizard needs to perform a certain ritual with a virgin to [[spoiler:create a dragon]]. This ritual may only be performed once every 100 years when the two moons align.
* In the vampire movie ''Film/OnceBitten'', 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.
* While not quite magical, in ''WesternAnimation/OnceUponAForest'', 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 uncurable.
* In ''Film/TheDarkCrystal'' 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 ''Film/{{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 [[JerkassHasAPoint actually raise a valid point]]: the rule is kind of vague.)
* In the silent film ''Film/TheGolem'', the Rabbi can only create the Golem while a certain astronomical constellation occurs. The occurence of another constellation supposedly causes the Golem to rebel.
[[/folder]]

[[folder:Literature]]
* In ''Literature/TheDresdenFiles'' universe, sunrise acts as a magical ResetButton. 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 [[GenreSavvy 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 [[spoiler:Halloween night]] is a time when even immortals can be killed.
* Similarly, in the ''Literature/OctoberDaye'' series, a number of spells dissipate at sunrise. But it doesn't last until sunrise. It lasts until the first birdsong is sung.
* In ''Literature/{{Discworld}}'', according to Death, [[foldercontrol]]

[[folder: The lawyers of Fate require a loophole. ]]
when dealing with prophecies.
* Similarly, in ''Literature/AGameOfUniverse'', 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 Creator/RobertEHoward's ConanTheBarbarian story ''Literature/ThePeopleOfTheBlackCircle'', the king is killed by magic on a certain date.
* In Creator/RobertEHoward's {{Kull}} / BranMakMorn 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 AdrianTchaikovsky's ''[[ShadowsOfTheApt Dragonfly Falling]]'', Uctebri explains he is awaiting the most auspicious date.
* In L. Jagi Lamplighter's ''[[ProsperosDaughter 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 Creator/EdgarRiceBurroughs's ''Literature/TheMonsterMen'', Chinese medicine is described as using this.
* In WenSpencer's ''{{Literature/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.
[[/folder]]

[[folder:Tabletop Games]]
* ''TabletopGame/ChangelingTheLost'': if you're lucky, contracts work until sunup or sundown, whichever happens first; or for free if you invoke FoodChains.
** also Pledges, Tokens, Goblins, and the True Fae.
* ''TabletopGame/VampireTheMasquerade'' and ''TabletopGame/VampireTheRequiem'' both have a few powers, usually BloodMagic, that end at sunrise.
* ''TabletopGame/DungeonsAndDragons'', 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 the ''TabletopGame/DungeonsAndDragons'' campaign world ''TabletopGame/{{Ravenloft}}'', adding a fanciful duration or an escape hatch when laying a curse makes it ''much'' more likely to take hold.
[[/folder]]

[[folder:Theater]]
* ''AMidsummerNightsDream'': The fairies show up WhenTheClockStrikesTwelve.
-->'''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:''
[[/folder]]

[[folder:Video Games]]
* In ''VideoGame/GhostTrick'', the ghost Sissel is told that he will vanish from this world at dawn. [[spoiler:It turns out that this is a lie to motivate him.]]
[[/folder]]

[[folder:Web Comics]]
* In ''Webcomic/TalesOfTheQuestor'', the hunt lasts until cockcrow. [[http://www.rhjunior.com/totq/00521.html Not mind you, dawn]]. (Good thing for ExactWords.)
* In ''Webcomic/WapsiSquare'', 2012 is not only WhenThePlanetsAlign, [[http://wapsisquare.com/comic/anyideas/ it's when you can do something about it]].
* In ''Webcomic/DreamKeepers Prelude'', [[http://www.dreamkeeperscomic.com/Prelude.php?pg=191 Namah deduces her show's on as if it were this.]]
* In ''Webcomic/{{Doodze}}'', [[http://seguemediagroup.com/doodze/?p=627 the sunlight only protects you as long as it's up.]]
* In ''Webcomic/{{Erstwhile}}'', [[http://www.erstwhiletales.com/a-tale-with-a-riddle-0-3/#.T29v9Nm6SuI the woman is allowed to go home only overnight.]]
* In ''Webcomic/DragonMango'', [[http://dragon-mango.com/comic/chapter05/dm05-46.htm making the seal had drawn on the raw power of the stars' alignment.]]
[[/folder]]

[[folder:Web Original]]
* In ''Literature/TalesOfWyre'', 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.
[[/folder]]

[[folder:Western Animation]]
* ''Disney/TheLittleMermaid'': The contract is made until the sunset on the third day. Covering sunsets and the rule of three.
* ''WesternAnimation/{{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 WordOfGod, 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 DepopulationBomb in "Hunter's Moon," for example, only works on the night of the Hunter's Moon. WordOfGod 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 ''RockosModernLife'', 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, [[HereWeGoAgain Heffer has an urge to go on a fast-food binge]], prompted by the alignment of every fast-food joint in O-Town.
[[/folder]]

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