Genre: 
Full text: 
Jam sol recedit igneus tu lux perennis unitas nostris beata trinitas infunde lumen cordibus | Te mane laudum carmine te deprecamur vespere digneris ut te supplices laudemus inter caelites | Patri simulque filio tibique sancte spiritus sicut fuit sit jugiter saeclum per omne gloria
Feast: 
Fulltext source: 
EC-Qsf 4; Breviarium Romanum (Rome 1632); https://www.preces-latinae.org/thesaurus/Hymni/IamSol.html
Notes: 
Urban VIII revision (1632 breviary); cf. 008358 for an earlier standard version, which has a different first line and extensive other differences