Hebrew-Gregorian Calendar Conversion

Olenberg.org

Hebrew-Gregorian Calendar Conversion

Whether transcribing gravestones or Hebrew/Yiddish writings,
this calculator will facilitate the conversion to, and from, Hebrew and Gregorian (civil) dates.

[Hebrew to Gregorian/Civil]

Please be aware that the date that the Gregorian calendar superceded the older Julian calendar, in various countries, varied from as early as October 15, 1582, in those countries where the Catholic Church had great influence, to as late as 1927 in Turkey. Thus, it is possible that you could determine a Gregorian date, for a particular Hebrew date, that is prior to the institution of the Gregorian calendar in the country of choice.
(Hence, in the United States, note the reference to George Washington's birthday, on calendars, as "traditional", February 11 (his actual birthday under the Julian calendar), and "celebrated", February 22nd, which is the Gregorian date...Washington was born in 1732, while Great Britain and its colonies switched to the Gregorian calendar in 1752. See more notes about various calendars, and calendar errors, below.)

WORLD CANDLE LIGHTING TIMES FROM TORAHTOTS.COM

Julian and Gregorian Calendars: The Julian calendar was established by Julius Caesar in what is now 46BC. After various changes by subsequent Roman emporers, it was more or less fixed by about 7AD. Unfortunately, the length of the average Julian calender year is slightly longer (about 11.5 minutes) than the average "solar" year...that is, the time it takes for the earth to complete one orbit around the sun is less than a year according to the calendar. This puts the calendar out of sync with the sun by about 7 days every 1000. That is, holidays, solstices & equinoxes occur earlier and earlier each year on the calendar. By the 1500, the error had accumulated to 12 days.

In 1582, Catholic Pope Gregory decreed a new calendar that dropped 10 days (a miscalculation of the accumulated calendar error that was two days too short): That year, in those countries that switched to the new "Gregorian calendar", October 4 was followed by October 15. To minimize future errors, 3 leap years out of 400 years were dropped. The new rule is that century years, ending in "00", must be evenly divisible by 400, rather than 4, in order to be a leap year: 1900 was not a leap year, but 2000 was. This minimized the accumulation of future errors, but it is not perfect because, now, the average calendar year is slightly shorter (+/-26 seconds) than the solar year. But, it now takes about 10,000 years for the error to accumulate to 3 days.

As noted above, the biggest problem with converting dates between calendars derives from different countries having adopted the Gregorian calendar at different times. The Polish kingdom adopted it as Pope Gregory decreed, in 1582, as did most predominantly Catholic countires (France, Italy, most of Germany, Holland, etc). But Great Britain and its colonies did not adopt it until September 14, 1752 (which immediately followed Sept 2). Russia, and Lithuania, did not adopt it until February 15, 1918, which immediately followed Feb 1. The last country to adopt the Gregorian calendar was Turkey, in 1927. To make a completely accurate conversion, you must know the date the Gregorian calendar went into effect into the country of choice.

When different dates are quoted. they may be identified by letter (J, Julian; G, Gregorian; H, Hebrew), or Julian dates may be reffered to as" Old Style", OS, & Gregorian as "New Style", NS. If both dates are listed, the first will usually be the Julian date. The abbreviations, BC & AD, by the way, are usually replaced with BCE and CE in Jewish writings: "Before the Common Era" & "Common Era".

Hebrew Calendar: If someone told you that Hanukah occurs on the same date every year, would you say he was wrong? He's not...if he is referring to the Hebrew calender, which fixes Hanukah as the 25th of Kislev every year. The problem is that the date varies on the Gregorian calendar because the year lengths are different in the two calendars. The Hebrew calendar is often referred to as a lunar calendar, but it actually takes the motions of both the sun and moon, and the earth's rotation, into account. In an attempt to keep in sync with the solar year, the Hebrew calendar has a complicated series of leap years (7 years out of each 19 in which an entire extra month, called Adar II, is added to keep the calendar in sync with the sun. In addition, a day is added or subtracted in different years to keep Rosh Hashonah from falling on the sabbath, and Yom Kippur from falling adjacent to the sabbath.

The Hebrew calendar is approximately twice as accurate as the Julian calendar was, but still not perfect. It accumulates an error of a full day approximately every 216 years: In its, approximately, 1600 years of existance, it is out of sync with the solar year by about 6-7 days, vs about 14 days, up to now, for the Julian. . This current Hebrew calendar was promulgated by Hillel II in the Jewish year 4119 (dated from creation, not from the origin of the Jews), which was Julian year 358/359AD. Because Hillel II was part of the Second Sanhedron, and it is assumed that only a similar body has the authority to alter the calendar, the Hebrew calendar will not be modified to correct for the accumulated error unless, and until, another Sanhedron comes into existence.