The following are only my thoughts with some facts incorporated to bring it all together, but it makes more sense to me concerning what I read in scripture than the Julian or the Gregorian calendars.
The orbit of the Moon around the Earth is not an easy process. The Moon makes a complete orbit around the Earth approximately once every 28 days. This means that the Moon orbits the Earth 13 times in a year.
28 days per month X 13 months = 364
364 days divided by 7 = 52 weeks per year
According to the book of Enoch, there are what we call windows of degrees concerning the sun, moon and stars. As we notice the sun rising and setting in different degrees (windows on the horizon) throughout the year, so are the moon phases in relationship to degrees. The windows of the sun and moon are determined by their alignment according to the constellations. This would cause the hours in each month's moon window (degree of rising and setting) to be longer or shorter depending on the time of year.
The synodic month is the time it takes the moon to reach the same visual phase. According to the instructions given by God, watchmen were placed, ready to sound the trumpet, when the first sliver of a new moon appeared, being a “new month.”
This varies notably throughout the year, but averages around 29.53 days. The synodic period is longer than the sidereal period because the Earth–Moon system moves in its orbit around the sun during each sidereal month, hence a longer period is required to achieve a similar alignment of Earth, the Sun, and the Moon.
The time (anomalistic) in which the moon passes from perigee to perigee is about 27.55 days. “Perigee” is the point at which the moon is nearest to the earth. The Earth–Moon separation determines the strength of the lunar tide raising force.
This is the high and low end of calculations, so it is important to understand that every month is not the same length of time to the minute. It would be more accurate to calculate each month, but I present this only as an example.
Days in shortest month = 27.55 X 9.4 months = 258.970 days
Days in longest month = 29.53 X 3.6 months = 106.308 days
258.970 + 106.308 = 365.278
Without going into great detail, there are 365.242 days per year, the Biblical calender having 13 months every year because they measured monthly time by the moon.
The average number of days per month = 28.54 = 684.96 hours per month.
684.96 hours divided by 28 days per month = 24.462857 average length of days year round, some days being shorter, and some longer according to the moon and sun's rotation.
Therefore, the average of hours for each day throughout the entire Biblical year equal approximately 24 hours 28 minutes per day year round in a 13 month moon cycle of 28 days each.
The Moon appears to move completely around the celestial sphere once in about 27.3 days as observed from the Earth. This is called a sidereal month, and reflects the corresponding orbital period of 27.3 days. The moon takes 29.5 days to return to the same point on the celestial sphere as referenced to the Sun because of the motion of the Earth around the Sun; this is called a synodic month (Lunar phases as observed from the Earth are correlated with the synodic month). Since the Moon must move eastward among the constellations enough to go completely around the sky (360 degrees) in 27.3 days, it must move eastward by 13.2 degrees each day. Thus, with respect to the background constellations the Moon will be about 13.2 degrees further East each day. Since the celestial sphere appears to turn 1 degree about every 4 minutes, the Moon crosses our celestial meridian about 13.2 x 4 = 52.8 minutes later each day.
Taking these calculations into account, we also know that there is an increase or decrease in the length of days as the times and seasons pass. We identify scripture as the 3[SUP]rd[/SUP] 6[SUP]th[/SUP] or 9[SUP]th[/SUP] hour when we read about the crucifixion of Christ, and compare that with our clock as 9am, 12noon, and 3PM. This is close, but not necessarily correct. The sun dictates the hour of the day according to the shadow on a “sun dial.”
The “sun dial of Ahaz” (Isaiah 38:8) calculated the shadow from morning to evening. As I understand, there were 12 increments within the bowl, each increment being defined as an hour. This couldn't have been a 60 minute time sequence when we take the hours of daylight into consideration between summer and winter.
In summary, unlike what I have found on the web concerning leap years, weekly Sabbaths, and the number of days per month, using these calculations above, it is easy to see that the weekly Sabbath days year round correlate perfectly with the “Feasts of Unleavened Bread,” “the Feast of Weeks,” and the “Feast of Tabernacles.” The weekly Sabbath days fall on the 1[SUP]st[/SUP], 8[SUP]th[/SUP], 15[SUP]th[/SUP], and 22[SUP]nd[/SUP] of each month year round, and they are in perfect synchronization with the moon.
I also have a different thought from what I had determined previously about the women who prepared spices for the body of Jesus, resting “according to the commandment.” I'll save that for a different post.