Date and Number Format by Country

In short Two things vary between countries and neither predicts the other. Dates run day-month-year in 30 of the 39 locales here, year-month-day in 8, and month-day-year in exactly 1 — the United States. Numbers vary independently: the decimal mark is a full stop in some countries and a comma in others, so 1.234,56 in Germany is the same quantity as 1,234.56 in Britain, and reading one as the other is wrong by a factor of a thousand. Britain writes dates the European way and numbers the American way; South Africa writes English and formats numbers continentally, so one point five is 1,5; Israel mixes them the other way again. Assuming a language tells you the number format is how a spreadsheet import silently corrupts a column. The part almost nobody publishes is the thousands separator itself. Six different characters do that job across these locales, and two of them are whitespace: an ordinary comma, a full stop, a no-break space at U+00A0 in eleven countries, a NARROW no-break space at U+202F in France alone, an apostrophe in Switzerland alone, and the Arabic thousands separator at U+066C in Saudi Arabia. France's space and Austria's space look identical on screen and are different bytes, which is precisely why a figure copied from a French document arrives in a spreadsheet as text rather than as a number, and why stripping spaces does not fix it. Every value on these pages was extracted from Intl rather than transcribed. That is worth one caveat, because it caught this page out: CLDR revisions reach different runtimes at different times, so Switzerland is currently U+0027 in Chrome 148 and still U+2019 in Node 22, and both bytes are in real documents. The per-country pages re-derive the thousands separator from your own browser and say so when it disagrees with the table.