This is mostly expected due to the way the date picker works.
However, we're no longer going to be relying on that date picker in the future and we will instead use native HTML5 date inputs. One benefit of these is it will display the date consistent with your browser locale. This does mean it won't necessarily match up with your language settings, precisely, if you happen to have them set to something specific, but should be correct for post people providing their browser locale is correct, and this should display correctly in RTL and displaying in, e.g. dd/mm/yyyy or mm/dd/yyyy rather than yyyy/mm/dd for everyone.
So we'll close this for now and you can expect improvements here in the future.