The options panel is displayed in Dutch.
My Windows display language is English UK.
My Windows location setting is UK.
My default and only keyboard setting is US International.
My Date/time/number formats is set to Dutch.
My timezone is set to GMT +1
How is it deciding on Dutch language? Surely, by now humanity must understand the difference between LANGUAGE and LOCALE ?
For display language, look at the display language.
For formatting dates, look at the locale.
The two are NOT dependent in any way, and one should NOT make any assumption from one towards to other.