UBS Dictionary of the Greek New Testament

Sense 1: eight

Semantic entry: 60.17

Semantic domains: Number

Subdomains: One, Two, Three, Etc. [Cardinals]

Definition: cardinal number, where there are eight instances of a countable entity

Notes: To designate a week, the normal practice in NT times was to speak of ‘eight days,’ since in a series both the first and the last days were counted. The equivalent in many languages would be simply ‘after seven days had passed’ (RV LUK 2:21 · LV LUK 2:21 · Read together LUK 2:21).