The Greek noun ephēmeria (ἐφημερία) means a daily service, a priestly division or course. It appears twice in the NT — Luke 1:5 and 1:8 — both referring to the priestly course of Abijah to which Zechariah belonged. The word derives from ephēmeros (daily, for the day) and refers to the system David established (1 Chr 24:1–19) of organizing priests into 24 rotating divisions for temple service.
Luke's mention of ephēmeria in the opening chapter of his Gospel anchors the narrative in the concrete liturgical life of Second Temple Judaism. Zechariah served in the division (ephēmeria) of Abijah, the eighth of David's 24 courses (1 Chr 24:10). Each course served in the temple for one week, twice a year. The lot that fell to Zechariah to burn incense (Luke 1:9) was a once-in-a-lifetime privilege, given the large number of priests. This providential detail sets the stage for the angelic announcement of John the Baptist's birth — God's new work begins within the rhythms of the old covenant's faithful worship.