calaqui tonatiuh.

Headword: 
calaqui tonatiuh.
Principal English Translation: 

for the sun to set, or for the sun to enter (the underworld)

Orthographic Variants: 
calaquin tonatiuh
Alonso de Molina: 

Calaquin tonatiuh. ponerse el sol. Preterito. ocalac in tonatiuh.
Alonso de Molina, Vocabulario en lengua mexicana y castellana, 1571, (www.idiez.org.mx), f. 11r.

Attestations from sources in English: 

auh in onquizca ie vmmotzcaloa, ie vncalaqui in tonatiuh = When they had come out the sun was already off to one side, about to set (Mexico City, sixteenth century)
James Lockhart, We People Here: Nahuatl Accounts of the Conquest of Mexico, Repertorium Columbianum v. 1 (Los Angeles: UCLA Center for Medieval and Renaissance Studies, 1993), 152.