The Calendar Drift

It is not here !!

In Gregorian Year 2214 (5974-5975) our Traditional Hebrew calendar is scheduled to drift out of balance by another day.

If the calendar is not fixed Passover will advance to Tuesday April 26 ~ May 3, 2214 (5974) .  In 2214 (5975) Rosh Hashanah will be on October 6 for the first time ever.

Please see the following excellent Remy Landau article on the Rosh Hashanah drift. http://hebrewcalendar.tripod.com/drift.html

If you want to review a great website about our Jewish Calendar, this site designed by Steve Morse is excellent. He gave me excellent input to my website: http://stevemorse.org/jcal/jcal.html . His page http://stevemorse.org/hebrewcalendar/hebrewcalendar.htm gives a great and simple explanation of the situation at hand. On the page the following sections :

With the fixed calendar the holidays and seasons will always be in balance. With the Fixed Calendar Passover will be on Sunday March 27, 2214 as it did in 1994 and will in 2146.  March 27th has been an acceptable start date for Passover since 3749 BCE.  

If you care to use the Traditional Calendar past 2214 the Alan D. Corré website is outstanding at http://wwwx.uwm.edu/cgi-bin/corre/calendar

Gregorian Calendar Drift

It Is Not here

If our standard Gregorian Calendar is not fixed, it could also cause a drift of the solar calendar.

It has been suggested (by the astronomer John Herschel (1792-1871) among others) that a better approximation to the length of the tropical year would be 365⁹⁶⁹/₄₀₀₀ days = 365.24225 days. This would dictate 969 leap years every 4000 years, rather than the 970 leap years mandated by the Gregorian calendar. This could be achieved by dropping one leap year from the Gregorian calendar every 4000 years, which would make years divisible by 4000 non-leap years.

This rule has however, not been officially adopted. It is used in the fixed calendar  to insure accuracy for the entire 28,000,000 year period covered.

Format has been in existence since 1767

That was before the United States Became a Nation

The calendar format for the Fixed Calendar has been in use since 1767 when September 5 became the earliest date to host Rosh Hashanah (March 26 to host Passover).

In 1815 October 5 became the latest date to host Rosh Hashanah (April 25 to host Passover). Since the system has worked so well for this extensive period the fixed calendar simply extends it another 28 million years.

Fixed Calendar format was accepted in 1815

The Jewish Calendar has been gradually drifting out of balance one Gregorian Day every 231.374 years. The longest period between drift dates is 399 years.

The largest date drift is two dates. In 1815 the latest date for Rosh Hashanah became October 5.   Before 1815 and since 1435 October 3 was the latest date.

The next drift from October 5 to October 6 is scheduled in 2214, that is 399 years.

The Gregorian Calendar was adopted in 1582.

The year 1815 was different because it was first drift in the Gregorian Calendar  (last drift in the Fixed Calendar).

It was the only time ever that the biggest and longest drift occurred in the same year.

The two-day drift of 1815 was a signal that something had to be done and we had 399 years to do it.  

In 1815 it appeared that the drift was not a concern and the dates of the calendar were accepted. It was left to modern programmers to act before 2214.

The Fixed Calendar is a proven and long-term solution to the calendar drift and it is something we can give to our future generations.

Fixed Calendar involves very minimal changes to the current calendar

It is extremely cost effective

There is really nothing to do to use the Fixed Calendar since it does not separate itself from the Traditional Jewish Calendar until 2214. You can use the same formula that has been used since 320CE by Hillel II. After 2213 the formula will still be good, the Leap Years will just be placed where needed by adding a single block of code.  The Fixed Calendar gives us plenty of time to prepare and involves very minimal time and costs to program.

If you are not into algebra and programming simply save   as one of your favorite sites.

Honors the Traditional First Day of Spring on March 25

Passover is always involved with April and the Traditional Spring Equinox

The sages established that March 25 of the Julian calendar was the date of the spring equinox. Because the Julian calendar followed the same calculations as Shmuelb's, the Halachic Vernal Equinox fell out on March 25 every year.

The Fixed Calendar honors the traditional Vernal Equinox by placing Passover as the first permissible date after the traditional Halachic Vernal Equinox of March 25. Passover is always between March 26 (2013, 2089, 2233*, 2461*, 2480*) and April 25 (1929, 1967, 2043, 2119, 2176, 2263, 2282).   * A Fixed Calendar Year

In the Gregorian Calendar April 25 is accepted as the latest date for Easter Sunday. In the Fixed Calendar Passover and Easter are in perfect alignment.

In ancient times our month of Nisan was named Abib. If you review the definition of Abib it is very similar to the definition of April. 

http://www.encyclo.co.uk/define/abib

http://www.encyclo.co.uk/define/april

In the Fixed Calendar Passover is always involved with April. In the earliest calendar the last days of Yom Tov are on April 1 – 2. In the latest calendar the Intermediate Days will never go into the month of May.

The argument can be made that Passover should not start during the Tropic of Taurus (April 20 or later). In the latest calendar the April 25 start is five days past the end of the Tropic of Aries. April 20 is the earliest date the sun can enter the Tropic of Taurus, it can vary depending on the year and time zone.

In the Fixed Calendar the earliest start date for Succoth is September 19 (Tropic of Virgo). In the earliest calendar, Succoth can start five days prior to the start of the Tropic of Libra. September 24 is the latest date the sun can enter the Tropic of Libra it can vary depending on the year and time zone.

In the Fixed Calendar, Passover (plus five days with Aries) and Succoth (minus five days with Libra) will even out between the Tropics.

With the Fixed Calendar in the average century Passover and Easter will fall together in 86 years, the other 14 years (1/7^th of the time) Passover will be a month later. We used the Gregorian 20^th Century in the calculation.

Even though the Fixed Calendar works well with our current Gregorian Calendar the separation years for Passover and Easter demonstrate that the Jewish People have their own calendar.

Uses Leap Years Only When Needed

The Fixed Calendar only uses Leap Years as needed instead of by a pre-determined cycle that places them in certain years whether they are needed or not.  

In the Fixed Calendar the method of figuring the Jewish Calendar is exactly the same as it is now, except it adds one additional rule (the border molad).

The rule of thumb is as follows “when Rosh Hashanah’s average molad is before 6:00 pm on September 15 (Jerusalem Calculation), the upcoming year will be a Leap Year”

The Fixed Calendar also accounts for the Gregorian Leap Year when February has 29 days by adding about 9 hours and 11 minutes.

There are Gregorian Common Years when time is subtracted to prevent the Rosh Hashanah from falling on October 6 the following year.

Over the 28,000-year Gregorian cycle the average border molad will be at 6:00 pm on September 15.

In the Fixed Calendar Tishrei's molad will show the time and the border molad for that year so you will always know if the upcoming Jewish Year will have 12 or 13 months.

You can view the calculations for the border molad at: http://www.fixedcalendar.org/BorderTypeForm.aspx

Since Tishrei is the 7^th month of our Jewish Calendar and in ancient times September was the 7^th month of Roman Calendar , placing the border molad in the middle of September is the most logical place for it.

Fixed Calendar automatically adjusts itself by subtracting unneeded seconds

When Hillel II designed the Jewish Calendar each month was calculated by using 29.530594135 days. Each astrological lunar phase is really 29.530588853 days. Even though this error is very small it will eventually cause Rosh Hashanah and Rosh Chodishs to drift away from the new moon.

To rectify the situation the Fixed Calendar subtracts 0.0000633874239355237 days or 5.47667342802925 seconds each year at the end of Elul. By making the adjustment once a year there is no need to change molad formulas that are in use today.

Since there are other calendar fixes and ideas out there and if the Fixed Calendar is adopted the first year that is adjusted is 2123g or 5884h. The reasons for selecting this year are:

1) It is still over 100 years away and it will not effect the dates of the traditional calendar until 2214 (see above paragraph).
 

2) By using this adjustment 90 years prior to the calendar taking full effect, it will make Tishrei’s molad in 2214g or 5975h occur exactly at 12:00 Noon Jerusalem time or 18:00 Rambam on Monday, September 5, 2214. (no minutes, seconds, parts).

The idea of adding or subtracting seconds to calendars has successfully been done before.
This site: http://www.usno.navy.mil/USNO/earth-orientation/eo-info/faq/what-is-a-leapsec gives an excellent explanation of the Leap Second.

Just by adding this simple adjustment the Fixed Calendar always guarantees that our Jewish Calendar will always be in complete sync with solar seasons and lunar phases.

 

Does not rely on Cycles

They can not be counted on anyway

The current Jewish Calendar operates in 19 year cycles in assigning Leap Years by the year in the cycle. The current method has caused this drift and encouraged the birth of the Fixed Calendar.

In the current cycle there are cases that the cycle year can not give an accurate picture of how the calendar should look:

1958 and 1977 are the 18th years of the cycle and 1977 ran 2 days behind 1958.

2008 - 2009 and 2027 - 2028 are the 11th and 12th years of the cycle. 2027-2028 run 2 days ahead of 2008 - 2009.

2088 and 2107 are the 15th year of the cycle and 2107 runs 3 days ahead of 2088. The same happened between 1888 and 1907 when 1907 ran 3 days ahead of 1888 both the 5th years of the cycle.

In the current cycle system the 8th year is always the latest calendar. In our upcoming cycle, 2024 is the 8th year and 2035 the 19th year is later by one day. 2043 will also run two days ahead of 2024 both the 8th years of the cycle.

There have been larger and better cycles suggested:

1) In 1931 Dr. William Moses Feldman suggested a 334- year cycle. After a period of several millennia the dates would start going backwards and another adjustment would have to be made.

2) Dr. Irv Bromberg suggested a 353- year cycle that is more accurate. Dr. Bromberg's site is very interesting and has a lot of great information on calendar reform. The Fixed Calendar nearly mirrors the Bromberg calendar every 353 years.

The Fixed Calendar is perpetually adjusting itself.  Drs. Feldman and Bromberg gave me the idea to fix the Jewish Calendar. The concerns I have with their cycles are:

1) They would start taking effect as early as 2016. With the fixed calendar we have until 2214 before it takes full effect.  

2) In these modified cycles there are Passovers that are entirely in March. The Fixed Calendar always makes Passover part of April and Chanukah part of December. Both of these calendars advocate different date ranges then we are currently using today.  If another set of dates are used, events that occurred in certain years would never enjoy having their Gregorian anniversaries on the Jewish Calendar date again.  My parents were married on October 25, 1959 (after sunset) or 24 Tishrei 5720 and my grandparents were married on November 28, 1929 or 25 Cheshvan 5690. With a new date range as suggested we would never enjoy celebrating these Gregorian dates on the Jewish Calendar dates again.   On May 14, 1948 or 5 Iyar 5708 we had our first Israeli Independence Day. In the Rectified Calendars 5 Iyar would never correspond to May 14 again.

Since I am the conservative type, I like having over 200 years to prepare and I prefer to stick with the current set dates we have enjoyed since 1767.

Always in Sync with the Gregorian Calendar

Even though it was not introduced by a Jewish person, the Gregorian Calendar plays a significant role in our society. I am certain that more Jewish people celebrate their birthdays on the Gregorian Date. Most Jewish people do not even know their Hebrew birthday. In Jewish Cemeteries most of the dates on the stones are Gregorian. Every Bar Mitzvah or wedding invitation I have received the dates are also Gregorian. When the neighborhood synagogue sends news letters the events are always listed with the Gregorian date.

There is no doubt that the Gregorian calendar and Jewish Calendar should be in sync. The Fixed Calendar carefully and thoughtfully places our Jewish events with our civil Gregorian Calendar.

Seasons and Tekufoth are always in alignment

Season and Tekufoth Calendar

In the Fixed Calendar all of the seasons fall in perfect alignment between the Gregorian and Hebrew Calendars.

In 1582 when the Gregorian Calendar came into circulation, 11 days were dropped and certain Gregorian Years that were divisible by 4 and 100 but not 400 became common years instead of leap years. In our current Gregorian Calendar 1700,1800,1900,2100,2200,2300, etc are common years. In the Fixed Calendar years that are divisible by 4000 are also common years.

In 1582 the Halachic Vernal Equinox advanced from March 25 to April 5. Every time that  there is a Gregorian Year that is divisible by 4 and it is common year the Halachic Vernal Equinox advances by one day.

In 1700 it advanced to April 6, In 1800 it advanced to April 7, In 1900 it advanced to April 8, In 2100 it will advance to April 9.

In the Fixed Calendar when the Halachic Equinox advances to April 12 or (1 week from the original equinox) the Equinox is set back one week as it will in 2500.

This adjustment guarantees that the Blessing of the Sun (see table) will never advance to the month of Iyar. Each major Solar Cycle of 28,000 years always contains  10,226,783 days. The average Julian Blessing of the Sun is on March 25 as originally attended.

Season and Tekufoth Calendar