Enji (Albanian: [ɛɲi]) is the old name of the fire god in the Albanian pagan mythology evidently contained in the weekday name that was dedicated to him – e enjte – the Albanian word for Thursday. The Fire – Zjarri – is deified in Albanian tradition as releaser of light and heat with the power to ward off darkness and evil, affect cosmic phenomena and give strength to the Sun (Dielli, who is worshiped as the god of light, sky and weather, giver of life, health and energy, and all-seeing eye), and as sustainer of the continuity between life and afterlife and between the generations. The divine power of Fire is used for the hearth and the rituals, including calendar fires, sacrificial offerings, divination, purification, and protection from big storms and other potentially harmful events. Fire worship and rituals are associated with the cult of the Sun (Dielli), the cult of the hearth (vatër) and the ancestor, and the cult of fertility in agriculture and animal husbandry. Fire rituals that are commonly found among Indo-European peoples, including the Albanians, have been firstly attested by the Vedas, with hymns dedicated to the fire god Agni. Described in written sources since 1482, the Albanian fire rituals have been historically fought by the Christian clergy, without success. The cult of the mystic fire and the fire ritual practices have played a prominent role in the lives of all the Albanian people until the 20th century, and in rural areas they continue to be important for Albanian traditional customs even in the present days.

The theonym from which Thursday was named in Albanian is considered to have been attested in antiquity in Illyrian theophoric names with the Latin spelling En(n)-. He was presumably worshiped by the Illyrians in antiquity and he may have been the most prominent god of the Albanian pantheon in Roman times by interpreting Jupiter, when weekday names were formed in the Albanian language. The belief in a prominent fire and wind god, who was referred to as I Verbti ("the blind one"), and who was often regarded more powerful than the Christian God, survived in northern Albania until recent times. Under Christianization the god of fire was demonized and considered a false god, and it was spread about that anyone who invoked him would be blinded by fire. The purifying power of fire underlies the Albanian folk belief according to which the fire god is the enemy of uncleanliness and the opponent of filth.

In Albanian tradition Fire is deeply respected. To spit into it is taboo. Albanian solemn oaths are taken "by fire", and the worst curse formulas are cast for the extinguishing of the individual's, family's and clan's fire. The lineage is identified with an original fire, and the members of a same tribe/clan are "from the same fire". Zjarri i Vatrës ("the Fire of the Hearth") is regarded as the offspring of the Sun and the sustainer of the continuity between the world of the living and that of the dead and between the generations, ensuring the survival of the lineage (fis or farë). The absence of fire in a house is traditionally considered a great curse. Protectors of the hearth are Gjarpri i Vatrës ("the Serpent of the Hearth"), a household benign serpent, and Nëna e Vatrës ("the Mother of the Hearth").

Zjarret e Vitit ("Ritual Calendar Fires") are associated with the cosmic cycle and the rhythms of agricultural and pastoral life. The ritual collective fires (based on the house, kinship, or neighborhood) or bonfires in yards (especially on high places) lit before sunrise to celebrate the main traditional Albanian festivities such as Dita e Verës (spring equinox), Shëngjergji, Shën Gjini–Shën Gjoni (summer solstice), the winter festivals (winter solstice), or mountain pilgrimages, often accompanied by animal sacrifices, are related to the cult of the Sun, and in particular they are practiced with the function to give strength to the Sun and to ward off evil according to the old beliefs. Zjarri i Gjallë, Zjarri i Egër, or Zjarri i Keq – traditionally kindled with rudimentary fire making tools and techniques – is the ritual purifying Fire used for the cleansing, protection, healing, and energizing of livestock and humans. Albanian folk beliefs regard the lightning as Zjarri i Qiellit ("the Fire of the Sky") and consider it as the "weapon of the deity". During big storms with torrential rains, lightning and hail, which often cause great damage to agriculture, livestock, and to the rural economy in general, Albanians traditionally bring outdoors Fire as a continuous chain or in a container, as well as ember and fire-related metallic objects, seeking assistance from the supernatural power of the Fire, in order to turn the storm away and to avert the harms it can cause to the community.

The root of the Albanian theonym contained in the word for "thursday" is thought to be found in antiquity in the Pannonian-Illyrian area, as well as in Messapia/Iapygia in southern Italy such as Ennius, interpreted as a theophoric name: "the one dedicated to En". Other examples with the same root and with the suffix -c (-k) are Enica, Enicus, Enicenius, and with the suffix -n are Eninna, Ennenia, and the short forms Enna and Enno. Compounds of the divine name En are Enoclia "En, the famous", and Malennius containing the Albanian term mal "mountain", interpreted as "the one dedicated to En of/from the mountain".

In his work Speculum Confessionis (1621) Pjetër Budi recorded the Albanian term tegnietenee madhe for the observance of Maundy Thursday (S.C., 148, vv. 26, 89). In his Latin-Albanian dictionary (Dictionarium latino-epiroticum, 1635), Frang Bardhi recorded dita ehegnete as the Albanian translation of Latin dies Iovis. In 1820, the French scholar François Pouqueville recorded two old Albanian terms: e igniete and e en-gnitia. In 1879 Albanian scholar and language master Kostandin Kristoforidhi translated Zeus / Δία of the original Greek text with the Albanian Ἒνετε Enete, and Hermes / Ἑρμῆν with the Albanian Μερκούρ Merkur.

Modern dialectal variations of "Thursday" include: Gheg Albanian: e êjte, e ẽjtë; Tosk Albanian: e enjtë; Arbëreshë Albanian: e ègn'te, e énjite, e ente, e engjte, e ínjte.

The noun zjarmi "fire" is firstly attested in the oldest known Albanian book – Gjon Buzuku's Missal, published in 1555.