Ngokomlando, isikhathi esiqondile kwachazwa nokusetshenziswa sundials. A isikhathi elihambisana usuku olulodwa 1/24, 1/24 a of the time phakathi ezimbili izindinyana the Sun at the zenith. Kodwa lokhu Clock World ukubala isikhathi universal ayilungile ngoba period kuphenduka eMhlabeni siyahluka athe eminyakeni edlule.
Nesikhathi esiqondile ngokuhamba kwesikhathi zones
A isikhathi zone yisici imbulunga lapho isikhathi kwezomthetho kuyafana yonke indawo. Umbono wokuqala ukwehlukana enguMhlaba ibe 24 esishintshashintshayo isikhathi sinye. The zone wokuqala isekelwe Greenwich onqamula of ikuphi 0. Uma umuntu maqembu zone isikhathi omunye, liyakhula isikhathi sendawo (kusuka entshonalanga kuya empumalanga) noma ukunciphisa (kusukela empumalanga kuya entshonalanga ) ihora elilodwa.