Yom (Hebrew: יום) is a Biblical Hebrew word which occurs in the Hebrew Bible. The word is a generic term meaning "a period of time". In both Modern and Biblical Hebrew it is usually translated as a specific period of time (such as "day", "evening", "lifetime", or "year") based on context.
Although yom is commonly rendered as "day" in English translations, the word is a generic term for a period of time and can be used in different ways to refer to different, context-based timespans:
Biblical Hebrew has a limited vocabulary, with fewer words than other languages, such as English or Spanish. Hence words often have multiple meanings, with the exact meaning determined by context. In Strong's Lexicon, yom is Hebrew #3117 יוֹם, from an unused root that means "to be hot, as the warm hours of the day".
Yom relates to the concept of time, and is used not just for "day" or "days", but for time in general. How yom is translated depends on context, using hermeneutics. The word day is used somewhat the same way in the English language, as in "back in my grandfather's day, cars did not go very fast" or "in the day of the dinosaurs there were not many mammals".
In English translations of the Holy Bible, yom is variously translated as "time" (Gen. 4:3, Is. 30:8), "year" (1 Kings 1:1, 2 Chronicles 21:19, Amos 4:4), "age" (Genesis 18:11, 24:1, 47:28; Joshua 23:1,2), "always" (Deuteronomy 5:29, 6:24, 14:23, and 2 Chronicles 18:7), "season" (Genesis 40:4, Joshua 24:7, 2 Chronicles 15:3), and as either "epoch" or "24-hour day" depending on interpretation (see Genesis 1:5,8,13,19,23,31 and 2:3; see also § Creationism below).
In the first Genesis creation narrative (Genesis 1:1–2:3), "yom" has been translated into English as "day", even though a day is the period of time that it takes for the Earth to complete one revolution on its axis and the Earth does not exist for the first and second "yom" (phases) of the creation narrative.
In both young- and old-Earth creationisms, the yom word can have several meanings, which depend on the context in which the word is used.
In gap creationism, yom is 24 hours, but there is a gap of time between Genesis 1:1 and 1:2, before the six consecutive days of creation. In day-age creationism, yom is timespan. For the progressives, it is also a generic time-span, but with time gaps. In evolutionary creationism, also known as theistic evolution (which seeks to harmonize the Bible and the theory of evolution), the literal interpretation of yom is either not crucial or (at times) metaphorical.
Hebrew scholars reject the rule that yôm with a number or an "evening and morning" construct can only refer to 24-hour days. Hugh Ross pointed out that the earliest reference to this rule dates back to 1970s young Earth creationist literature and that no reference to it exists independent of the young Earth movement.
The word Yom is used in the names of various Jewish feast days; as, Yom Kippur, the Day of Atonement; and Yom Teruah (lit., day of shouting), the biblical name for Rosh Hashannah, the Feast of Trumpets.
Yom is also used in the name of each of the days of the week in the Hebrew calendar.
Lexical Summary: 1. a day (as the warm hours), whether literal (from sunrise to sunset, or from one sunset to the next), or figurative (a space of time defined by an associated term), (often used adverb) / Strong's Exhaustive Concordance: age, always, continually, daily, birth, each, today,
NASB Translation afternoon* (1), age (8), age* (1), all (1), always* (14), amount* (2), battle (1), birthday* (1), Chronicles* (38), completely* (1), continually* (14), course* (1), daily (22), daily the days (1), day (1115), day of the days (1), day that the period (1), day's (6), day's every day (1), daylight* (1), days (635), days on the day (1), days to day (1), days you shall daily (1), days ago (1), days' (11), each (1), each day (4), entire (2), eternity (1), evening* (1), ever in your life* (1), every day (2), fate (1), first (5), forever* (11), forevermore* (1), full (5), full year (1), future* (1), holiday* (3), later* (2), length (1), life (12), life* (1), lifetime (2), lifetime* (1), live (1), long (2), long as i live (1), long* (11), midday* (1), now (5), older* (1), once (2), period (3), perpetually* (2), present (1), recently (1), reigns (1), ripe* (1), short-lived* (1), so long* (1), some time (1), survived* (2), time (45), time* (1), times* (2), today (172), today* (1), usual (1), very old* (1), when (10), when the days (1), whenever (1), while (3), whole (2), year (10), yearly (5), years (13), yesterday* (1).
yō·wm 'e·ḥāḏ – the first day