EXPLANATION OF BIBLICAL YEAR AND MONTHS - The original design by God is 364 days a year with some months being 31 days and others being 30 days. Therefore the average month consists of 30.3 days (Enoch 72:32; Jubilees 6:32). The average month was 30 days based on the 150day difference between the 17th day of the 2nd month (Gen. 7:11; Gen. 8:3) and the 17th day of the 7th month (Gen. 8:4). Therefore the remaining 7 months would have some months being 31 days.

When the law was given to Moses, the sacred year starts with Abib/ Nisan being the 1st month of the year (Exo. 12:2; Exo. 13:4; Est. 3:7) and there are 12 months a year (Est. 3:7; 1 Kings 4:7). The new moon was the start of every month as per the example of the Passover; where the 1st day of the month was a new moon to enable the Passover to be on a full moon, the 14th day (Exo. 12:6; Exo. 13:10; Psa. 81:3; Lev. 23:5-6). However, due to the sin in the world, the solar cycle slowed down causing the moon cycle to be out of order (Jubilees 6:38). There were generally 12 months a year (Est. 3:7). The solar year changed from 364 days to 365.25 days per year and the month cycle slowed down from an average of 30.3 days to 30.4 days per month. The moon cycle is ~29.5 days per cycle x 12 = 354days. Therefore, if one uses the 12month moon cycle only, then the various feasts such as “feast of first fruits” would have on occasion, happened in the winter. Therefore, the months need to match the solar calendar for the festivals to coincide with the seasonal harvests (Exo. 13:15-16; Lev. 23:9-14). In order to adjust this, the Israelites periodically added a month to a year. The month Adar II was added at the end of the 12th month, at a frequency of 7 times during a 19year cycle to make up for this discrepancy (every ~3years). This meant a leap year would be 383/385 days.

An interesting note is that the counting of years of “Jubilee” did not start at Abib but started from the 10th

day of the 7th month (Lev. 25:9-17). But the counting of years starts at the 1st of Abib, when the Israelites came out of Egypt (Num. 1:1; 1 Kings 6:1).

Another interesting note is that although today many Jews keep the Passover on the 15th of Abib/ Nisan, there are a few who keep it on the 14th. The issue is understanding when twilight is. Is it at the start or end of the Biblical day as there is only one twilight per day? We know that the Biblical day starts at evening and finishes in the day (Gen. 1:5), but does it start at the sun setting/ below the horizon (twilight) or at total darkness? First, we need to understand that the 15th Abib is a High Sabbath, Unleavened Bread, a day of rest (Lev. 23:6; Num. 28:17). Therefore, if twilight on the 14th Abib is at the end of the 14th day then the Disciples would have eaten the Passover in the evening on the 15th Abib. Yeshua didn’t have it one day earlier but had it on the specific Passover time. In addition, the events that followed such as carrying of clubs, Jewish holding hearings etc, would not have been done on the High Sabbath day. Therefore, it is only logical that Yeshua and the 1st Century Jews kept Passover at the start of 14th Abib being twilight, the 15th Abib (High Sabbath) would be 24hours later. Therefore, twilight in scripture is at the start of the Biblical day. This is when night starts as the sun has set, and it continues until after dawn. Dawn would also be part of the night (Mar 1:35).

During the 7year world Tribulation period, the solar calendar seems to speed up for the first half and slow down for the next half. In the 1st 3.5 years when the 2 witnesses are on earth and protecting the Temple of God (Rev. 11:2-3) there is an average of 30 days per month and a year is 360days. This is based on the 1st 1,260days (Rev. 12:6) which is 3.5 years (Dan. 12:7; Rev. 12:14), and 1,260 days is in the middle of the 7years when 2 Witnesses are killed, the daily sacrifices stop and the Beast takes possession of the Temple of God (Dan. 9:27).

When the 2 Witnesses are gone, the sacrifices stop and the Beast takes possession of the Temple (Dan. 9:27), the Beast is killed (Rev. 13:3; Rev. 13:14) and the Dragon gives him power to continue reigning for another 42 months, causing abominations in the Temple of God for 1,290 days (Rev. 13:5; Dan. 12:11). Therefore the last 3.5 years will be 1,290 days (42months) which is an average 30.7days a month 368.6 days per year. To summarize the first 3.5years = 1,260days and the second 3.5years = 1290days. God seems to have changed the solar calendar or the solar calendar was changed based of the level of sin. After the first 3.5 years, the change is more drastic (8 days different), and maybe this is the impetus for the Beast to change the times (Dan. 7:25).

https://heavenscatalyst.org/truth/revelation-commentary/