Catholic Encyclopedia (1913)/Rerum Deus Tenax Vigor

The daily hymn for None in the Roman Breviary, comprises (like the hymns for Terce and Sext) only two stanzas of iambic dimeters together with a doxology varying according to the feast or season. As in the hymns for Prime, Sext, and Compline, the theme is found in the steady march of the sun that defines the periods of the day: