The purpose of a calendar is to let you know when it is time to do the plowing, planting, breeding of cattle, and, in the industrial world, have coats ready for sale just in time for the cold weather. If it fails in this function, it fails to deserve the time and effort it requires. This brings up an interesting point about the Gregorian calendar. Pope Gregory 13th knew it was still some days off, and would get further off as the years progressed, but when his calendar-makers explained the situation, he dismissed the idea of correcting it to be more accurate than the version they presented, saying, “Do not burden the people more than they already are,” referring to the 11-day correction that had been indicated at the beginning of the project. The accurate correction would have been just short of a month. The majority of the people were already renters, and to have the rents come due 11 days early was already sufficient to cause riots in some places.
The current days behind the “sun time” is 15 days on the Gregorian calendar, so that Spring falls on the 15th day of the month instead of the 1st.
The other change that was politically inspired and expedient to get the Gregorian calendar accepted by the Roman Senate was to start the year on the start date of their annual assembly, January 1st, instead of the Spring equinox, when it had started in all cultures on every calendar since Noah got off the ark.
The result is that we have a Gregorian calendar that is neither accurate to the seasons nor accurate to the long term requirements.
The jubilee calendar, on the other hand, is accurate to at least 10,000 years, possibly longer, as that is as far as the calculations were carried out.
Here is the way the Gregorian and Qumran calendars fit to the seasons.
First, the Qumran calendar in a year-by-year layout for 2015 and 2016 until the end of October, then the temperatures month-by-month with notations of the date of the Spring and Autumn equinoxes and Summer and Winter solstices for the same periods.
The yellow squares on the left are the seasons. The yellow places to the right are days that have been intercalated as the various catastrophes, changes in the length of earth’s orbit due to external forces, upset the number of days. There are 12 months of 30 days each, with intercalations (added weeks) at various intervals. Here is the calendar for 2016.
Now for the temperatures. The date of the named days that begin each season are noted below the appropriate chart.
When the temperatures are compared to the seasonal changes, they correspond to within 2 days one side or the other, as does the Jubilee calendar to the actual astronomical solstices and equinoxes.
The calendar at Qumran has been updated periodically according to the changes in the days in the year, usually as a result of some catastrophic event, such as the comet that passed over India during the days of the Exodus that caused Mount Thera to erupt. The last update was done by King Hezekiah after the earthquake in the days of King Uzza, so it is necessary to differentiate which update is under discussion. The Hezekiah update is the one found at Qumran, so can be referred to as either the Qumran calendar or the Hezekiah calendar. Both are valid.
There are years when Summer comes early, and years when Autumn lingers. Both are the result of the 7th year Land Sabbaths, when one week is intercalated, and/or the 50th year jubilee, when an entire year containing an extra 2 weeks (except for the 350th and 700th years, when only 1 week is intercalated ), named but not counted among the counting of years, are inserted into the calendar.
A farmer who plants his crops by the current Gregorian calendar will have crop failures in those years. The farmer who plants by the Jubilee calendar will be safe from early rains and early frosts. Sheep-herders who breed their flocks by the Jubilee calendar will have a significantly higher survival rate among their lambs than those following the Gregorian calendar.
A color print of the Qumran Jubilee calendar can be downloaded free here. Pull a copy and observe for yourself, in your own area, whether the seasonal changes conform to the Qumran calendar or the Gregorian (or other local) calendar.