Using a standard western setup, in regards to .fods format fo:text-align="right" is not right-aligned, but fo:text-align="end" is.
This can be reproduced as follows:
1. Open a blank calc sheet in a std western setup
2. Enter some distinctive text in the first cell eg aaa
3. Save as a .fods then close it
4. Open the resulting file in notepad and search for your distinctive text then note the style id then jump to its style def using the find feature.
You'll see that right-aligning in Calc has been saved as fo:text-align="end". This will open correctly but (with it not open in Calc) if you now in notepad edit "end" to be "right" then save and open it in Calc, it will be left aligned. The spec does quite reasonably give "right" as a valid value.
@Regina, any opinion here?
fo:text-align="right" and fo:text-align="left" are valid attributes. So it is a missing feature.
The values "start" and "end" are used in Writer tables and in tables exported by Excel too. Therefore I think, it would be sufficient to convert "right" and "left" according actual writing-mode on import. In XSL-FO https://www.w3.org/TR/xsl/#d0e4611 they are converted for rendering purpose anyway.
NEW, then. Not sure, which meta bug this should go to.