This is the version I know, from that old war-horse, Carols for Choirs vol I.

According to the footnote, the refrain is traditional and the verses below by G R Woodward; tune in London Waits, from Chappell's Popular Music of the Olden Time. The harmonisation in Carols for Choirs is by Charles Wood:

Past three a clock,
And a cold frosty morning,
Past three a clock;
Good morrow, masters all!

Born is a Baby,
Gentle as may be,
Son of the eternal
Father supernal.

Seraph quire singeth,
Angel bell ringeth;
Hark how they rime it,
Time it and chime it.

Mid earth rejoices
Hearing such voices
e'ertofore so well
Carolling Nowell.

Hinds o'er the pearly
Dewy lawn early
Seek the high Stranger
Laid in the manger.

Cheese from the dairy
Bring they for Mary
And, not for money,
Butter and honey.

Light out of star-land
Leadeth from far land
Princes, to meet him,
Worship and greet him.

Myrrh from full coffer,
Incense they offer;
Nor is the golden
Nugget withholden.

Thus they: I pray you,
Up, sirs, nor stay you
Till ye confess him
Likewise and bless him.