Dates & Calendars (Gregorian, Julian, Hebrew, other)

I’m interested on any feedback / advice about use of RM9 for recording dates of events that are not based on the Gregorian calendar, e.g. use of Julian or other calendars. I understand that use of the Gregorian calendar varies by location and period. Typical guidance for recording events is to record the actual date of an event based on / transcribed from original sources. Things get a little more interesting if one has family members that come from places where there was late adoption of the Gregorian calendar, like in Asia, or if one has Jewish ancestors where traditional Hebrew calendar applies. Thoughts anyone?

Does anyone know what this means for sorting of events by dates within RM9 - e.g. does RM9 take a generic approach internally for dates and convert them to a Julian Date Number or similar as a way to support common representation across calendars?

Finally, does the interface to Ancestry / FamilySearch used by RM9 allow support for different dating systems / calendars?

Appreciate any feedback.

Did you review the Wiki here? RM Date Formats It answers some of your questions. I do not know what date formats FamilySearch accepts.

Thank you for making time for a reply and referring to the Wiki.

Yes, I have read the Wiki. Reflecting on my inquiry, I suspect it probably was too broad and hence the reason for lack of responses aside from your own.

The Wiki confirms what I already know. Default calendar for dates is Gregorian which replaced the Julian calendar as documented and there is support for dual dating between those calendar systems. Additional calendar supported is the Quaker.

What is not documented in the wiki is reference to other calendars identified in the Gedcom 5.5.1 standard: Hebrew and French Revolution. These are also in Gedcom v7. So, I assume these are not currently supported in RM8/9. For Jewish research for example, I assume then any folk using RM for this activity use the default of the Gregorian calendar.

I do know that work underway with improving Gedcom v7.x is potential expansion of the support of a larger number of calendars. In my fossicking around the site, I spotted reference of up to 80 other calendars already identified and support for them would need to be undertaken in an incremental approach. So, my earlier inquiry about support for calendars with interface to Ancestry / FamilySearch and RM9, as suggested by you (thank you), will require me raising questions with the respective data platform providers and not Rootsmagic and co.

While the Gregorian calendar has become a common civil, world standard, there are many other calendars in use around the world for cultural and religious reasons e.g. Chinese, Islam, Persian to mention just a few. I am interested in knowing how to support varied calendars with my family history research efforts. We shall wait and see what is revealed in future versions of RM to assist!

I do admit to getting ahead of myself on my point about using a common means for sorting of events with dates in the RM product assuming multiple calendars (beyond that already documented) can be supported at once in a database. So I suppose this really is a future feature request? My reference to Julian Date Number (not to be confused with Julian Date) was my initial thought on one proven way to tackle this - getting ahead of myself again.

Anyway, thank you. This monologue is already too long, so I’ll stop.

I don’t think that your original question was too broad BUT rather that

  1. Most people probably have never accessed records that used another calendar such as Hebrew, French Revolution, Quaker, Chinese etc…
  2. As for the Julian and Gregorian Calendars-- like me, most people probably knew abt it BUT really didn’t give it much thought UNLESS they ran across a dual dated record-which I have not YET!!!

Once a long time ago, when I was 1st starting out, I did look at some Quaker records and probably did NOT understand their dating system–so just copied the info as written but that was the only time I’ve ever accessed Quaker records…

According to the Wiki, you can use almost any date format you want-- if RM recognizes the format such as 7th da 3rd mo 1782 ( Quaker) , it will automatically fill in the sort date of March 7, 1782-- if however you use a birth date it does NOT recognize such as 4 Nissan, 5513 (Hebrew)-- the date will turn a pale yellow and you MUST supply the sort date 8 April 1753 --otherwise there is no sort date saved but the birth date is listed in the fact-- there are good calculators online…

As for Familysearch and Ancestry-- it is best to just call them and ask as I tried Googling it and can’t find an answer—
for anybody interested here is a nice chart from


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Thank you for the informative reply. The subject of calendars is potentially a “rabbit hole” subject which I find fascinating. The following link to Cyndi’s List about calendars and dates is certainly not trivial for those interested to explore further.

In my own research I’ve already come across the dual date scenario with Julian / Gregorian dates and have a need to look at others …


For those who are interested in calendars and algorithms for conversion between them, I can suggest the following :wink: “light” read : Edward M. Reingold and Nachum Dershowitz, Calendrical Calculations, Ultimate Edition. (New York, NY: Cambridge University Press, 2018), ISBN 978–1–107–68316–7.

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I played around a little trying to see what ( if anything) Ancestry would accept via a gedcom as I don’t use tree share–and found some very interesting things–so let’s start with the Hebrew Calendar…
If you put that Mel Acorn was born 13th Iyyar, 5543 and do a gedcom–Ancestry will NOT accept it and there is no birth fact at all listed for Mel even though there is in your file.

BUT if you customize the birth fact ( marriage/ death ec) by putting a checkmark in description then add <[desc]> to your sentence, Ancestry will accept it.

That said–Ancestry really does NOT know what to do with such a date, so your reports are going to be off-- normal reports will say how old the parents were when the child was born-- how old the person was when married/ died etc-- well Ancestry can’t figure that out–not sure if it would make a difference if the whole family line was listed with Hebrew date BUT suspect not- thought abt using an alternative date as secondary BUT that didn’t make a difference–so reports would probably be better from RM especially if you include facts.

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Quaker dates on Ancestry are accept no matter which way you do it ( with or without descriptions).

and the reports will turn out just fine as Ancestry can convert the Quaker date

whoops-- must edit this sorry-- seems Ancestry does NOT convert the Quaker dates just fine as I put Tom was born 7 da(y) 3 mo(nth) 1799 and Ancestry translates it to mean July 3 1799 which is odd BECAUSE Ancestry says all dates should be in the form of date/month/ year which is what was used

tried changing it in RM 9 to say 3mo 7th day 1799 and RM defaults it back to 7th da 3 mo 1799-- also tried changing the date to 15th da 3 mo 1799-- Ancestry would NOT accept that either ( with or without a description added)-- so it appears that you can only upload a gedcom with Quaker days from 1-12 and then Ancestry won’t translate the day and month correctly in most cases…

Bottom line is to add your Quaker dates on your Ancestry file and it will correctly translate the date in the report and put the Quaker date as the birth date in the fact page

Total side note, but in case you care …

  • I checked on MyHeritage and they don’t appear to have a way to specify calendar on the web interface. Rather surprising, since they’re particularly focused on Jewish ancestry. Their Family Tree Builder desktop app does appear to support the Hebrew and French Revolution calendars to a certain degree.
  • The GRAMPS app for Linux does support multiple calendars.

Tangential to RM, of course. But it does seem like RM, with it’s far greater user base than a Linux app, would benefit from broader calendar support. As you said …

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@nkess @KimberlyGreen

Great to read about your explorations of calendars further. Love it. IMHO this is an important subject area that needs far greater focus with online and offline tools used to record family histories.

As a side note, a common feature that has popped up in various family tree tool offerings, is the ability to have historical facts and timelines as visual / reporting contexts merged with family tree data. So, I imagine it would be very powerful if such could be aligned with relevant calendar for differing cultures / ethnicities. Another future feature request to add to RM list.


Ab-so-freaking-lutely! In fact, until that capability exists I use an external platform to create timelines that blend historical facts with my own ancestry information. It’s a timeline service called Preceden. But I would pay a premium to have that ability integrated into an actual genealogy platform.

Seeing if Ancestry supports dual dates has been a challenge-- have uploaded my database at least 15 times trying to work out ways for the use of all these different dates…
Part of the problem is how RM 9 deals with dual dates-- if you put a dual date of 1719/1720-- RM 9 puts it as 1719/20 but if you put 1751/1752 RM 9 puts it as 1751/2–Ancestry does NOT like the use of 1751/2-- you can add a dual date to the person on your Ancestry tree by adding the fact on Ancestry BUT it will give you the warning message that this is NOT a valid date or may contain more than 1 year value–are you sure you want to use it-- if you say yes, it will show up on the fact page and the reports seem to be okay…
There are 2 ways to get the dual dates on Ancestry when you use a gedcom –
You can use the 1751/2 scenario BUT Ancestry doesn’t translate the date right in the reports-- it again translate this as born Feb 1751-- YOU MUST USE DESCRIPTION on the RM FACT to get them to show up on the Ancestry fact page…

Best thing to do is put born Jan 8, 1751 OR Jan 8, 1752-- you don’t have to use the description here BUT I would to explain why you marked this as such and put in the description something like dual date of 1751/1751 recorded on document…

Ouch! That is most interesting. I will also do some further scrutiny and compare with some other tools in the shed. It appears to be harder than it needs to be given the this dual date scenario has been around for years. (shaking of head)

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I had a look at Preceden … a bit of deja vu, when I did agile software dev … clever to repurpose for family history.

Agile software dev?!?! I’m have a Professional Scrum Master cert from and RTE cert from ScaledAgile. :heart_eyes:

Thanks! I have several swimlanes dedicated to various areas of history (border changes, statehoods, wars, pop culture, etc) and then layers for each generation of my family. I can collapse / re-arrange swimlands as needed to get a better visual context. Below are some screen caps (the full view is miniture to maintain my personal info).

To bring it back to RM … just imagine if RM had a visualization tool like that. Wouldn’t that be spiffy?!

:star_struck: thank you for sharing the landscapes, wonderful. I agree, that it would be great to have that type of capability within RM. In RM7, there exists the capability to create custom charts which is flexible enough to enable similar visuals but with slightly more effort. Unfortunately, that flexible diagramming capability does not appear in later versions of RM (from what I can discern so far).

Your mention of agile brings back memories of time constrained sprints, minimal viable product releases and sessions on design thinking. The good old days. The challenges of software dev was convincing peers that design and coding were not the same … so many UIs ended up on rework rubbish heap because of they were not treated separate … memories … now I just focus on my own bespoke projects.

YES —It is MUCH harder than it needs to be-- my gosh when I was uploading trees to ROOTSWEB almost 20 years ago, they asked you if you wanted to USE DUAL DATES— don’t remember if they offered other calendars-- they also had at least 3 pages of questions you were asked such as cut off date for living is 1930–do you want to change that–do you want to upload notes and on and on-- now what you get is this…

Anyway–hope it helps

From “Andy Clarke via RootsMagic Community” <>
Date 4/10/2023 7:41:05 PM
Subject [RootsMagic Community] [RootsMagic] Dates & Calendars (Gregorian, Julian, Hebrew, other)

Every bit helps!
On GEDCOM, oh don’t let me get started … I know first hand that depending on which tool one chooses to use, if you attempt data exchange between other tools, there will be data loss because respective development interests have a slightly different way on implementing the GEDCOM standard(s) due to combo of standard inconsistency and developer interpretation. Calendars, dates are examples of areas inconstancy. Associations are another. Citations are another. End of rant.

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This book has an interesting title “ A book of 189 Calendars for AD 1752 to 1940 inc. (on CD)”. It’s available for $9.50 US at Archive CD Books. In the past I’ve bought quite a few reference CDs from them and they’ve been high quality.

But, I don’t think that I want to broaden my calendar knowledge this much.

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Thank you for the reference. I’m already in the rabbit hole …

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