Only very doubtfully ascribed, mind you, but any excuse to post it will do.
Rerum, Deus, tenax vigor,
immotus in te permanens,
lucis diurnae tempora
Largire clarum vespere,
quo vita numquam decidat,
sed praemium mortis sacrae
perennis instet gloria.
Praesta, Pater piissime,
Patrique compar Unice,
cum Spiritu Paraclito
regnans per omne saeculum.
And, because I can't choose which I like best, here are two beautiful translations:
O God, the world's sustaining force,
Thyself unmoved, all motion's source,
who, from the morn till evening's ray,
dost through its changes guide the day;
O grant us light at eventide,
that life may unimpaired abide,
and that a holy death may be
the door of immortality.
Almighty Father, hear our cry
through Jesus Christ our Lord most high,
who with the Holy Ghost and thee
doth live and reign eternally.
J.M. Neale and the editors of Hymns Ancient and Modern (1904)
O Strength and Stay upholding all creation,
Who ever dost Thyself unmoved abide;
Yet day by day the light in due gradation
From hour to hour through all its changes guide.
Grant to life’s day a calm unclouded ending,
An eve untouched by shadows of decay,
The brightness of a holy deathbed blending
With dawning glories of the eternal day.
Hear us, O Father, gracious and forgiving,
Through Jesus Christ Thy co-eternal Word,
Who, with the Holy Ghost, by all things living
Now and to endless ages art adored.
J. Ellerton and F. J. A. Hort