I want the default thousands separator to be a space instead of a comma. I’ve figured out how to do so manually. But how do I change the default so that when I activate the thousands separator, it adds a space automatically instead of a comma?
You’d need to choose a default locale (Tools → Options → Language Settings → Languages, Formats, Locale setting) that uses a space character as group (aka thousands) separator. Individual separators aren’t implemented yet.
I doubt that. You may have figured out how to insert a literal space in a number at a specific position, like
#" "##0
(and that’s always part of the display string also for smaller numbers just that you don’t see it) but that wouldn’t insert a separator at higher positions like it would not format 1000000 as 1 000 000
but as 1000 000
.
Let’s light ten candles for bug tdf#46448 (born 2012-02-22).
No. An ordinary space ( and also a 4-per-em space e.g.) is accepted basically as a group separator if inserted without the stringquotes. What you get for a number isn’t a string then, but a formatted number. Try # ### ### ##0.00
(U+0023U+2005U+0023U+0023U+0023U+2005U+0023U+0023U+0023U+2005U+0023U+0023U+0030U+002EU+0030U+0030)
However, the functionality is limited, and the Boolean read-only-property .ThousandsSeparator
of the NumberFormat object remains False
.
The limitation I talk of is that no automatic group length is created. My above example has a 4-per-em space in front of every third digit left of the decimal separator, and it will work. but the created formatted number will have leading spaces then if it has less digits than the prepared format.
I suppose it shouldn’t be very difficult to fix the two mentioned issues. Anyway this and the additonal enhancements listed in the above linked bug must be implemented to eventually get a consistent solution allowing to define ISO-compliant defaults.
It’s a pity that LibreOffice still rattens well considered standards just as MS junk does.
BTW: The German letter standard by DIN for dates is YYYY-MM-DD
(allowing for exceptions), but this seems to not even be teached in apprenticeship training. Is this just a matter of power or are rational considerations still allowed?. .

No. An ordinary space ( and also a 4-per-em space e.g.) is accepted basically as a group separator if inserted without the stringquotes.
That’s the same if the space is not a separator and it is treated as a literal space, it’s even stored identical in ODF and loaded as #" "##0
.

Try
# ### ### ##0.00
Yes, but the display string will always contain two spaces, regardless of the number to display. You’ll see if you left justify or copy&paste to a cell content.

the created formatted number will have leading spaces then if it has less digits than the prepared format.
We could “waste” conditional formatting:
IF < 1000 / IF < 1000000 should do for most cases…