THE 4 WATCHES OF THE NIGHT. Mark 6:48

The 4 watches of the night synchronize well with the tabulation of John 19:14

Look at the division of the Israelite time clock. See how the final fourth watch of the night ends perfectly after the Roman 3 AM time slot when the night is welcoming the daylight as the night has been preparing to leave the shift to the sun for the morning watch and so forth!
Therefore, the biblical first hour starts at 4 PM Jewish Standard Time and at the same clock time on earth.

If we're missing just 1 commandment in our belief system, we will not be saved because we are not without sin, that is, we are not holy. The grace of Jesus is for the holy ones, according to Ezekiel 33:13-20.

Ezekiel 33:13 ASV
(13)  When I say to the righteous, that he shall surely live; if he trust to his righteousness, and commit iniquity, none of his righteous deeds shall be remembered; but in his iniquity that he hath committed, therein shall he die.