Strong's G3574 — νυχθήμερον (noun)
nuchthemeron (nookh-thay'-mer-on) n.
1. a day-and-night, i.e. full day of twenty-four hours
[from G3571 and G2250]
KJV: night and day 
Root(s): G3571, G2250 
Hebrew root: ἡμέρα
Occurrences: 1