Oge anyanwụ
. Oge nkuzi bụ oge nke oge dabere na ọnọdụ na mbara igwe . ụbụrụ bụ isi nke oge bụ ụbọchị, dabere na oge ntụgharị synodic . Omenala, e nwere ụdị nke atọ nke ọkara oge dabere na astronomical tara: oge mme poly poly na-egosipụta oge ( ndịre n' akụkụ a), na sidereal oge, nke na-egosi na ngosipụta nke ndị na-eso ụzọ Sun.
Osisi toro ogologo nke edobere n'ala na-eme dị iche iche anwụ anwụ na-acha. N'otu oge n'ụbọchị,kaa ahụ ga-atụ aka kpọmkwem n'ebe ugwu ma ọ bụ n'ebe ndịda (ma ọ bụ na-enwe ike n'anya mgbe ma ọ bụrụ na-enweta na-aga n'elu). Oge ahụ bụ ehihie na mpaghara ehihie, ma ọ bụ elekere 12:00 o doro anya na mpaghara. Ihe dị ka awa iri na anọ na anɔ gachara, akara ga-akpa aka n'ebe ugwu-ndịda, na-adị ka ọ kpuchiri ogo ogo 360 n'ụdị axis ụwa. kpuchiri kpọmkwem ogo 15 (Mgbe1/24 nke gburugburu, a na-atụkwa abụọ ahụ n'akpaelu na-adaba na axis ụwa), oge obodo ahụ bụ 13:00 kpọmkwem; mgbe 15 ọzọ degrees ọ ga-abụ 14:00 kpọmkwem.
Nsogbu bụ na na September Sun na-ewe obere oge (dị ka elekere ziri ezi) iji mee elele ìhè ihe ka ọ na-eme na December; 24 "awa" nke ihe nwe ike ịbụ 21. Nke a iwu na- quantified site nhata nke oge, na bụ n'ihi na eccentricity nke Earth si orbit (dị ka na, Earth's orbit bụghị n'ụzọ zuru okè, nke nwanna na-amata – Sun anya iche n'ime afọ. ), na eziokwu na Earth axis bụ. ọ bụghị perpendicular na ụgbọ elu nke orbit ya (ihe a na-akpọ obliquity nke ecliptic ).