1: σάββατον
(Strong's #4521 — Noun Neuter — sabbaton — sab'-bat-on )

is used (a) in the plural in the phrase "the first day of the week," Matthew 28:1; Mark 16:2,9; Luke 24:1; John 20:1,19; Acts 20:7; 1—Corinthians 16:2 . For this idiomatic use of the word see ONE , A, (5); (b) in the singular, Luke 18:12 , "twice in the week," lit., "twice of the sabbath," i.e., "twice in the days after the sabbath." See SABBATH.