Date and time refuse to be translated

Hi everyone,

All of the languages show English time and date for me. I tried to get untranslated strings but nothing about date and time showed up.
apps/frappe/frappe/public/js/frappe/misc/pretty_date.js or moment with locates - I guess one of these files handle the date/time format.

@ferohers do you want to dig in momentjs, let us know if you need help.

i face the same problem even though it fit all requirement to be translated
in pretty_date.js

return when = day_diff == 0 && (
			diff < 60 && __("just now") ||
			diff < 120 && __("1 minute ago") ||
			diff < 3600 && __("{0} minutes ago", [Math.floor( diff / 60 )]) ||
			diff < 7200 && __("1 hour ago") ||
			diff < 86400 && ("{0} hours ago", [Math.floor( diff / 3600 )])) ||
		day_diff == 1 && __("Yesterday") ||
		day_diff < 7 && __("{0} days ago", day_diff) ||
		day_diff < 31 && __("{0} weeks ago", [Math.ceil( day_diff / 7 )]) ||
		day_diff < 365 && __("{0} months ago", [Math.ceil( day_diff / 30)]) ||
		__("> {0} year(s) ago", [Math.floor( day_diff / 365 )]);
}

and in frappe translate is translated correctly . but it dos not change when i change main lang of the system
what the best practice to make it translated correctly based on lang ??