Oh, thank you all for the the great suggestions! I have been away from my computer for a couple of days, and now I am shocked by the Sisyphus work awaiting me to check the alternatives.
Please bear with me if it takes its time.
But I'll be back!

Thank you! It was indeed set to 1899 , but so were some of my other spreadsheets too, while some others were set at 1904. I didn't know I had to set this individually for each spreadsheet. However, none of the others (so far) have had that weird behaviour of changing dates every time I open it. Now ...

This is strange: I made an ods file with a short list of our vaccinations in the family, showing which vaccines we took and on which date we took them. Date format 2023-10-11. Every time I reopen the document, it has subtracted 5 to 10 years from the year digits, and one day from the day digits. :sh...

Thanks for the answers. At least it's a relief to see that it's not just that I'm too dumb to find the algorithms by myself.

Maybe I used the wrong search words, but I couldn't find anything on this. Pls excuse non-native English; hope you can understand my question: I would like some formulae to simulate what would happen with the long-term accumulated earnings or losses with a volatile stock if I say I want my worth of ...

The current version is later than mine. I tried several times to update, but only get this unhelpful warning in a dialog named " Missing string:1204 " The first line then says Missing string:1226 followed by a rectangle containing the text, Missing string:1214. Then below the rectangle it ...

Thanks! Fixed my signature now.

You ( okjhum) didn't create a signature nor tell otherwise your OS. Anyway: If you want to give LibO another try, simply use a portable pack (PrortableApps package for windows, e..g.). It only needs to extract the contained files into an empty directory, and doesn't touch your AOO install. (For my ...

Really sorry for that. Just updated the responsible file in the source by adding the new era. New era was indeed missing before, Should become available in new releases now. After that Calc should display your new era correctly. If not, please let us know at dev@openoffice.apache.org Thank you DiGr...

Thank you. Actually I tried to migrate to LibreOffice a couple of years ago. It looked so promising. But all my dates were randomly messed up in the conversion and made my Calc sheets completely useless. So I restored my backups and warned myself from ever daring to try again. :( This Reiwa thing is...

Hi, I can't find a way for Calc to display the present Japanese era (Reiwa 苓和) correctly. I tried several ways, but Calc only returns it as the last era (Heisei 平成) as if it didn't change three years ago. So it does display even older years such as Showa (昭和) correctly, but just not Reiwa, unless I ...

- or can you import sheets from OO to Libre? Beware of that import! I tried, but many (if not most) of my dates were messed up, so I quickly deleted LibreO from my computer. Obviously OO and LO use different year systems, but it's beyond my competence and available time to find out how to remedy th...

Quite frankly, Months are an irregular unit. Is a month 28, 29, 30 or 31 days? If you are trying to map a recurring problem, days are a better unit. True, very true, but, e.g., 967 days doesn't tell my dysarithmetic brain much, and the exactness is not that important. So I prefer something comprehe...

The easiest method is to switch to LibreOffice for this project, and use the included DATEDIF function. If you prefer OpenOffice, you can have both installed at the same time. LibreOffice seemed so nice, so I installed it ... but in the conversion from OpenOffice, most of my dates were so severely ...

Lieber Herr Lupp aus München (wo meine Schwester lebt - aber ich in Schweden)! Vielen Dank! I tried to concatenate your helper formulae from cells D:J into one monster formula but failed. As I don't want to have too many columns in my pages, I'll stick to my approximate formula for the time being. T...

I would be interested in a real-world example where results of such formulas are actually useful or even needed. I'm keeping a log of my migrating RA attacks and symptoms at various locations (joints and tendons) to detect any trends in progress or regress. The fine details of time (+/- one or more...

...]Sorry. That's not acceptable. Fairly correct must be correct. If there are exceptions they should be named and the reasons should be analysed. Then the given suggestion must be set under the respective restrictions. I applyed the suggested "fairly correct" formula many times on a samp...

Ah, "why 11 days?" → because the first day is a day 1, not zero. :knock: So for inclusive calculation I added +1 at the end. I also changed from TRUNC to ROUND in the beginning of the day calculation. When I put ROUND at more places, I got bigger errors. Finally, I now multiply the last fa...

I came up with this unelegant formula that however seems to give fairly but not completely correct answers: =TRUNC((end-start)/365,25) &" yr " &INT(((end-start)/365,25-TRUNC((end-start)/365,25))*12) &" mo " &TRUNC((((end-start)/365,25-TRUNC((end-start)/365,25))*12...

gerard24's formulae (Jan 26, 2017) for months and days don't work for me. soby's formulae (Jan 26, 2017) only work as long as the numerical values of the enddate month and/or day are/is larger than of the startdate. In that example the period from 2003-05-12 to 2006-06-30 is 3 years 1 months 18 days...

Thank you all! I hadn't understood that DATE could be used in this way. The simplest formula by Lupp worked perfectly after I added a term (TODAY()-D2)/365,26 giving the present age also:
=DATE(YEAR(D2)+(TODAY()-D2)/365,26+1;MONTH(D2);DAY(D2))
Problem solved -- thanks again!
Olle

Sorry if this was dealt with already, but I did search and couldn't find the answer: How do I add a full year to a given date so that the result can be used for further date calculations? Specifically, I have a spreadsheet with peoples' birthdays, producing a little text like " John's 22nd birt...

Thank you, but I wouldn't call this "directly", as there are several clicks to finish it. Is there a keyboard shortcut for a time stamp, as in Excel? (Ctrl+-) I don't seem to manage to create one myself, because I only get to the "Insert function", not the function itself =NOW() ...

I'm using v. 2.0.2, English version on Win XP sp2 I got a "read-error". Can't find this topic in the web site. I was writing an odt document with lots of jpg pictures and mixed Japanese and Swedish text with "Rubies" text added. Afraid of losing something, I almost manically save...