The Julian calendar, proposed by Julius Caesar in 708 Ab urbe condita, was a reform of the Roman calendar. It took effect by edict, it was designed with the aid of Greek mathematicians and Greek astronomers such as Sosigenes of Alexandria. The calendar was the predominant calendar in the Roman world, most of Europe, in European settlements in the Americas and elsewhere, until it was replaced by the Gregorian calendar, promulgated in 1582 by Pope Gregory XIII; the Julian calendar is still used in parts of the Eastern Orthodox Church and in parts of Oriental Orthodoxy as well as by the Berbers. During the 20th and 21st centuries, a date according to the Julian calendar is 13 days earlier than its corresponding Gregorian date; the ordinary year in the previous Roman calendar consisted for a total of 355 days. In addition, a 27- or 28-day intercalary month, the Mensis Intercalaris, was sometimes inserted between February and March; this intercalary month was formed by inserting 23 days after the first 23 days of February.

The net effect was to add 23 days to the year, forming an intercalary year of 377 or 378 days. Some say the mensis intercalaris always had 27 days and began on either the first or the second day after the Terminalia. According to the writers Censorinus and Macrobius, the ideal intercalary cycle consisted of ordinary years of 355 days alternating with intercalary years, alternately 377 and 378 days long. In this system, the average Roman year would have had ​366 1⁄4 days over four years, giving it an average drift of one day per year relative to any solstice or equinox. Macrobius describes a further refinement whereby, in one 8-year period within a 24-year cycle, there were only three intercalary years, each of 377 days; this refinement averages the length of the year to 365.25 days over 24 years. In practice, intercalations did not occur systematically according to any of these ideal systems, but were determined by the pontifices. So far as can be determined from the historical evidence, they were much less regular than these ideal schemes suggest.

They occurred every second or third year, but were sometimes omitted for much longer, occurred in two consecutive years. If managed this system could have allowed the Roman year to stay aligned to a tropical year. However, since the pontifices were politicians, because a Roman magistrate's term of office corresponded with a calendar year, this power was prone to abuse: a pontifex could lengthen a year in which he or one of his political allies was in office, or refuse to lengthen one in which his opponents were in power. If too many intercalations were omitted, as happened after the Second Punic War and during the Civil Wars, the calendar would drift out of alignment with the tropical year. Moreover, because intercalations were determined quite late, the average Roman citizen did not know the date if he were some distance from the city. For these reasons, the last years of the pre-Julian calendar were known as "years of confusion"; the problems became acute during the years of Julius Caesar's pontificate before the reform, 63–46 BC, when there were only five intercalary months, none of which were during the five Roman years before 46 BC.

Caesar's reform was intended to solve this problem permanently, by creating a calendar that remained aligned to the sun without any human intervention. This proved useful soon after the new calendar came into effect. Varro used it in 37 BC to fix calendar dates for the start of the four seasons, which would have been impossible only 8 years earlier. A century when Pliny dated the winter solstice to 25 December because the sun entered the 8th degree of Capricorn on that date, this stability had become an ordinary fact of life. Although the approximation of ​365 1⁄4 days for the tropical year had been known for a long time ancient solar calendars had used less precise periods, resulting in gradual misalignment of the calendar with the seasons; the octaeteris, a cycle of 8 lunar years popularised by Cleostratus, used in some early Greek calendars, notably in Athens, is 1.53 days longer than eight Julian years. The length of nineteen years in the cycle of Meton was 6,940 days, six hours longer than the mean Julian year.

The mean Julian year was the basis of the 76-year cycle devised by Callippus to improve the Metonic cycle. In Persia after the reform in the Persian calendar by introduction of the Persian Zoroastrian calendar in 503 BC and afterwards, the first day of the year slipped against the vernal equinox at the rate of one day every four years. In the Egyptian calendar, a fixed year of 365 days was in use, drifting by one day against the sun in four years. An unsuccessful attempt to add an extra day every fourth year was made in 238 BC. Caesar experienced this "wandering" or "vague" calendar in that country, he landed in the Nile delta in October 48 BC and soon became embroiled in the Ptolemaic dynastic war after Cleopatra managed to be "introduced" to him in Alexandria. Caesar imposed a peace, a banquet was held to celebrate the event. Lucan depicted Caesar talking to a wise man called Acoreus during the feast, stating his intention to create a calendar more perfect than that of Eudoxus, but the war soon resumed and Caesar was at

Earth Warp is a story produced by the BBC as part of their Look and Read programme. It aired on BBC Two from 11 January to 22 March 1994; the story was 10 episodes long and focused on pollution. It has been repeated many times since the original broadcast, as as 2009. One hundred years ago, Aliens sent a probe to Earth; the purpose of this probe was to monitor the pollution levels of the Earth. One day the probe signals the aliens. A plump little alien, called Ollie, comes to investigate the town of Southbeach because of the probe; the town is suffering from a mysterious illness found in the children due to pollutants being pumped into the sea by a local factory. The local children befriend Ollie, who informs them that the pollution in Earth's atmosphere is causing things created by his species – like the probe – to malfunction, he informs them that the malfunctioning probe is going to explode. This would start a chain reaction. OllieA plump little alien from the planet Gia-'Ollie' is an approximate version of his name, as his real name is unpronounceable in English-, who comes to Earth to investigate after receiving a signal from the probe, his species sent.

He has the ability to shrink. He possesses a mysterious ball which can be used to fix broken and/or damaged objects and cure the illness being caused by the pollutants, he can summon his hidden spaceship by whistling. Prolonged exposure to Earth's atmosphere makes him uncoordinated and will weaken him. MartinOne of the three friends who are amongst the first to encounter Ollie, his mother owns a hotel, doing badly due to the mysterious illness. He has Asthma, although it is unclear whether Ollie's mysterious ball cures him along with those infected with the mysterious virus. During the series he betrays Ollie to try to save the hotel, although he pretends to be Ollie to draw the resulting officials away. AminaOne of the three friends who are amongst the first to encounter Ollie, she cares for the environment and wishes that all people could be bothered to care as well, she is headstrong and takes the role as leader of the group. It is revealed that Ollie chose to reveal himself to her because he could sense her caring nature and thought she could help him.

In the series to cover for Olle's increasing hunger and clumsiness, she pretends that she can do magic to account for some of the objects he has knocked over while invisible, which gets the attention of the press. During their investigation into the pollution, she gets sick; this is cured by Ollie using his mysterious ball, which Ollie gives to her before his departure after she used it to cure him of his weakness. JennyOne of the three friends who are amongst the first to encounter Ollie, she cares for Martin and persuades Amina and Ollie that he is a good person. Her judgement seems to be misplaced when Martin betrays Ollie to Lowin, but soon after her beliefs are confirmed when Martin draws the authorities away from Ollie. Mrs. RowlandsMartin's mother, manager of The Burlington Hotel where the children conceal Ollie, throughout the series she tries to keep from selling the hotel to Mr. Belcher doing so in one episode. At the end of the series the events of the series cause mass bookings and make the hotel a success again.

Joe LowinA reporter investigating the mysterious illness. He is the one, he has a desire to make it big and get a big story for his paper "The Daily News", he dislikes other reporters, shown in the way he speaks to Sarah, at the end of the series when the children give their story to Sarah first he quits the reporting business. Although in the educational section of the programme, he is referred to by Chris and Sarah as though he's become a member of staff of the Gasset. Mr. BelcherA factory owner dumping dangerous waste into the sea, attempting to conceal this activity, he attempts to buy the hotel from Martin's mother, he nearly succeeds at one point, although he comes to realise the danger of his actions when his daughter, becomes sick from the illness. He is arrested and fined at the end of the series after the authorities find out about his illegal activities, although he redeems himself by helping Ollie reach the probe before it explodes at the last minute. Sarah BrightlyA reporter from "The Southbeach Gazette" as well as the narrator of the story and one of the 3 characters in the education section of the episodes, she is Jenny's role model and an Eco Warrior.

Throughout the series, she tries to find the cause of the illness, she takes an interest when Anita starts doing magic. Chef played by Mark BentonOne of the staff working at the hotel, He seems to be fond of Mrs. Rowlands and his constant jokes are a source of annoyance to Martin. On a walk near the river he starts whistling, Ollie's ship hears him, thinking Ollie is summoning it, rises to find him, seeing that it isn't Ollie it utters a low growling apology and returns to the depths. After the experience the Chef tries to forget about it, but has a hard time, with everything else going on. Jenny's DadHe works in Mr. Belcher's factory, but refuses to continue due to the potential damage the job is causing to the environment and quits when Anita falls ill though Belcher claims to have fired him first. At the end of the series, he gets his job back, under a eco-friendly boss. ClareMr. Belcher's daughter, she spends most of the series i

Events from the year 1856 in art. May 1 – Charles Lutwidge Dodgson takes up photography as a hobby August 25 – Dante Gabriel Rossetti first encounters Fanny Cornforth in a London pleasure garden. Philip Hermogenes Calderon – Broken Vows Samuel Colman – Meadows and Wildflowers at Conway William Powell Frith – Many Happy Returns of the Day Hiroshige – One Hundred Famous Views of Edo Arthur Hughes – April Love William Holman Hunt – The Scapegoat Jean Auguste Dominique Ingres Madame Moitessier La Source Sir Edwin Landseer – Saved Baron Carlo Marochetti – Richard Coeur de Lion John Everett Millais Autumn Leaves The Blind Girl Peace Concluded Jean-François Millet – Shepherdess Seated on a Rock Eugene von Guerard – View of Geelong Henry Wallis – The Death of Chatterton January 7 – Charles Harold Davis, American landscape painter January 8 – Elizabeth Taylor, American painter January 12 – John Singer Sargent, Florentine-born American portrait painter March 8 – Colin Campbell Cooper, American impressionist painter March 9 – Tom Roberts, Australian painter March 11 – Georges Petit, French art dealer May 20 – Henri-Edmond Cross, French neo-impressionist painter October 28 Carolina Benedicks-Bruce, Swedish sculptor Anna Elizabeth Klumpke, American portrait and genre painter November 6 – Jefferson David Chalfant, American trompe-l'œil painter November 18 – Joakim Skovgaard, Danish painter November 21 – Eveleen Tennant, English portrait photographer Undated – Harry Fidler, English equine painter January 4 – David d'Angers, French sculptor and engraver April 5 – František Horčička, Czech history and portrait painter April 27 – Louis Joseph César Ducornet, French painter July 4 – István Ferenczy, Hungarian sculptor July 19 – Henry Aston Barker, Scottish landscape and panorama painter July 22 – Thomas Doughty, American landscape painter September 1 – Sir Richard Westmacott, English sculptor October – Rafael Tegeo, Spanish Neoclassical painter October 8 – Théodore Chassériau, French Romantic painter October 10 – Gim Jeong-hui, Korean calligrapher and artist October 25 – Naitō Toyomasa, Japanese sculptor of netsuke from Tanba Province October 28 – Johann Peter Krafft, German-Austrian painter November 4 – Hippolyte Delaroche, French painter November 6 – Cephas Thompson, American portrait painter November 13 – Ludwig Buchhorn, German painter and engraver November 21 – Charles de Steuben, French painter November 23 – Thomas Seddon, English landscape painter date unknown Pieter Godfried Bertichen, Dutch painter and lithographer Jean-Baptiste-Joseph Duchesne, French painter and miniaturist Elisabeth Charlotta Karsten and Russian painter Frederick Nash, English painter and draughtsman