According to the Bible, when does a day begin?

Hello,

Thank you for your question.

First of all, we must establish what the word “day” means. In the Old Testament, thus the Hebrew, the original word for day used was יוֹם or “yowm”. In the New Testament, thus Greek, the word for day used was ἡμέρα or “hēmera”. Both words, yowm and hēmera, can be used to represent day light, or a day in a week. So when we ask “when does a day begin?” we must differentiate between “day” as in day light (12 hours) or day as in a calendar date (24 hours).

When does the period of day light begin?

There is no debate as when the day for day light begins, as the Bible clearly states that its the time of day when there’s light:

“And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day” (Genesis 1:5).

The light is called day, and the dark is called night, and the completion of evening (sundown to sunset) and the completion of morning (sunrise to sunset) make up a day. This brings up the next question:

When does a complete 24 hour day begin?

Certain Lunar Sabbath believers state that the day is only the period of day light, and that the 24 hour day begins at sunrise. We, on the other hand, choose to believe as the Bible says that “the evening and morning” were the first, second, third, etc… day:

“And the evening and the morning were the first day … And the evening and the morning were the second day … And the evening and the morning were the third day … And the evening and the morning were the fourth day … And the evening and the morning were the fifth day … And the evening and the morning were the sixth day.”
Genesis 1:5,8,13, 18, 23, & 31.

Sadly, certain Lunar Sabbath believers ignored the fact that the evening and morning make up a day, and as a result, they not only begin their day at morning, but also just keep the Sabbath hours during the hours of the day (morning until sundown).