Thursday, October 9, 2008

Hebrew Date Conversion

Approximately 10 days ago would have been my great grandmother, Bertha Cruvant's 121st or 122nd birthday. As I posted in my weekly list of upcoming family events, I don't know what her birthday is on the Gregorian Calendar. I only know her birthday on the Hebrew Calendar, as she was born on Rosh HaShana, the Jewish New Year. The Gregorian date depends upon what year she was born, which is unknown.

Her family used the Gregorian/Civil calendar for most events, so we know the Gregorian birthdays for all her siblings. However, since her birthday fell on a religious holiday, that was the date remembered.

As her birthday approached it occurred to me: I wonder which of my relatives share birthdays or anniversaries on the religious calendar? I wondered how I would go about figuring this out. Two people born on Oct 7th, 2008 and Sept 18, 1999 would actually share the Hebrew birthday of 8 Tishri, but I have recorded the Hebrew dates for very very few events in my database - and in those cases the only place to record them has been in the notes.

There are online calendar converters that can convert between the two calendars, such as the one at hebcal. However, I'd have to go through every event in my database, plug it into the conversion program, and enter the results in an excel table or something. That would take a long time, and I figured this was the perfect thing for a software program to accomplish. I searched for some online, but was unable to find anything for the Mac.

The only genealogy software I could find that probably can accomplish this is Dorotree. However, there is no Mac version, so I haven't been able to test it.

One of the reasons I like my genealogy software, IFamily, is that it isn't a product of some huge company that releases (pricey) updates once-a-year on average. The developer is continually releasing (free) updates, and continually soliciting suggestions for new features. So I posted the suggestion in the forums that the On This Day feature that currently allows one to see all the events that occurred on a single day be modified to generate a list for a Hebrew date. Have the software convert all the dates for me, and see which ones match up.

The newest version now does this. [Version 2.464 / It isn't released yet, but can be requested.] Once again, I am not aware that any other genealogy program for the Mac has this feature yet. If one does, let me know in the comments.

Now I know that in addition to being the birthday of my great-grandmother, Rosh Hashana (Tishri 1) is also the anniversary of the death of my great aunt, Thelma (Malpe) Newmark (Sept 18, 2001), and the birthday of my second great uncle, Abe Gold (Sept 19, 1895).

Today, Tishri 10 (the Jewish holiday of Yom Kippur), is the birthday of my 2nd great-aunt Blanche Blatt (Sept 28, 1887), and is also among other events the 4th birthday (Sept 25, 2004) of the daughter of a cousin of mine, though I intentionally don't name living relatives on my blog, and have erased the names associated with the recent events in the image below.

[*Note* The software feature makes no adjustment for time-of-day. Therefore if an event occurred on the Gregorian calender after sunset, but before midnight, the Hebrew date conversion will be one day off. Since it is rare that I know the time of day for an event, this isn't a concern for me. But it could be important to remember for those cases where time-of-day is known.]


Schelly Talalay Dardashti said...

Hi, John,
The Hebrew calendar conversion at Steve Morse is excellent. Put in the Gregorian date and get the Jewish one or vice versa. Also, a nice calendar with the holidays marked (Jewish/Gregorian months).

John said...

For conversion of single dates, I prefer Hebcal. It provides a link to the text of the Torah portion, and at least HebCal warns you when you enter a date predating the Gregorian calendar, that it doesn't correct for those ten days. [Neither warns the user that prior to Year 70 CE, the Hebrew Calendar was 'observational' and the month only changed when two observers noted a new crescent moon. So no accurate conversion is possible pre-70 CE.]

Steve Morse's batch function would have been useful if I hadn't gotten the developer of the iFamily software to add a Hebrew Date function to their event calendar.

It might be possible on some software programs to export an excel spreadsheet of events - and then copy the Date Column, paste the date columnn into Steve Morse's Batch converter, and then copy/paste the results into a new column on the excel spreadsheet.