Perhaps some help with the Question 7 is in order, so that we may have a more detailed response from the Scripture.
The Scripture delineates when the Day [time] ends and when Night [time] begins,and what constitutes a standard Day:
Genesis 1:5 KJV - [5] And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day.
Job 38:12 KJV - [12] Hast thou commanded the morning since thy days; and caused the dayspring to know his place;
Judges 19:9, 25 KJV - [9] And when the man rose up to depart, he, and his concubine, and his servant, his father in law, the damsel's father, said unto him, Behold, now the day draweth toward evening, I pray you tarry all night: behold, the day groweth to an end, lodge here, that thine heart may be merry; and to morrow get you early on your way, that thou mayest go home. ... [25] But the men would not hearken to him: so the man took his concubine, and brought her forth unto them; and they knew her, and abused her all the night until the morning: and when the day began to spring, they let her go.
Mark 1:32 KJV - [32] And at even, when the sun did set, they brought unto him all that were diseased, and them that were possessed with devils.
Luke 1:78 KJV - [78] Through the tender mercy of our God; whereby the dayspring from on high hath visited us,
* Jesus is called the "Sun of Righteousness" which would "arise" - Malachi 4:2, etc
How can we find out if there are a specific number of hours in a standard Day? Let us turn again to Scripture:
John 11:9 KJV - [9] Jesus answered, Are there not twelve hours in the day? If any man walk in the day, he stumbleth not, because he seeth the light of this world.
Jesus said that there are normally "twelve hours" in the standard "day" time, which would also mean that there would be "twelve hours" also for the Night time. God from the beginning had separated the Light and Dark parts of the Day equally, and as through seasons came, the hours of each would fluctuate between one another.
Yet the Scripture also includes mere portions of any given part of "day" or "night" to count for a whole day. For instance - Genesis 7:4,10, 17:12, 42:17-19; 2 Chronicles 10:5,12; Esther 4:16, 5:1; Luke 1:59, 2:21; Acts 10:3-30, etc.
Thus the Maximum Time that the "day and night" portion of a single day [without Divine intervention] can be is 24 hrs and so the Maximum Time of the phrase "three days and three nights" would be 72 hours.
Night - 12 Hours
Day - 12 Hours
Night - 12 Hours
Day - 12 Hours
Night - 12 Hours
Day - 12 Hours
The Minimum time then for a single "day and night" could then be any portion of that "day" and any portion of that "night", thus even a measurement of mere minutes. We could count from 1 minute to Sunset, and 1 minute after Sunset, and still accurately represent the singular phrase "day and night" in a given context.
Notice that it does not have to be the Maximum, nor of the Minimum, but anywhere at either end and in between.
Context will determine for us how to proceed in determining whether we need to understand the Maximum, the Minimum or somewhere in between them.
We also know that we are not merely dealing with a single "day and night", but rather "three days and three nights".
This means that the Maximum amount of time can only be 72 hrs, being consecutive in time due to context, but that the Minimum amount of time can be approximately 48 hrs and 2 minutes, or even mere seconds in technicality or if Rabinical time, 3rd star visibly appears. See the inclusive reckoning:
Night - 1 minute before daylight, sunrise, etc
Day - 12 hours
Night - 12 hours
Day - 12 hours
Night - 12 hours
Day - 1 minute after daylight, sunrise, etc
There are other uses of the word Day, in Scripture which are also representative of either Prophetic time or of time "with the LORD". In those specific instances then, a "Day", being both of the "light" and "dark" parts:
[1] "each day for a year" - Numbers 14:34; Ezekiel 4:6, etc.
These speak when God is dealing with Prophetic time, but notice that the Prophetic time is based in the Literal 24hr Day of Genesis.
[2] "one day is with the Lord as a thousand years, and a thousand years as one day" - 2 Peter 3:8
"For a thousand years in thy sight are but as yesterday when it is past, and as a watch in the night." - Psalms 90:4
* Please note that 2 Peter 3:8 and Psalms 90:4 do not speak of plurality of thousand, but singular. These passages speak of the "Days" "with the LORD", from Creation, since this earth is approx 6,000 years old as of this point, and there is to come a final 1,000th year, being the 7,000th year, found in Revelation 20. These "Days" "with the LORD" are again based in the 7 Literal Days of Genesis. Hence the final "Day", the 7th Day of the Cosmic Week of God is known as the "Day of the LORD", being based in the LORD's Day, the 7th Day Sabbath of the Week.
It is obvious we are not dealing with either of these two in the "three days and three nights" of Jonah/Jonas, since the context reveals that we are dealing with regular days - Jesus basing His "three days and three nights" in the foundation of Jonas'.
Jonah 1:17 KJV - [17] Now the LORD had prepared a great fish to swallow up Jonah. And Jonah was in the belly of the fish three days and three nights.
Matthew 12:40 KJV - [40] For as Jonas was three days and three nights in the whale's belly; so shall the Son of man be three days and three nights in the heart of the earth.
We simply have to understand the Events of Jonah, and where we are to begin counting for Jesus' "three days and three nights", which are based in Jonah's historical events. We will need to further consider what the "heart of the earth" is, in relation to Jonah being in the Sea Creature.
