Globalize
A JavaScript library for internationalization and localization
...Obviously, each language has different names for the days of the week and the months of the year. But they also have different expectations for the structure of dates, such as what order the day, month and year are in. In number formatting, not only does the character used to delineate number groupings and the decimal portion differ, but the placement of those characters differs as well. Globalize provides number formatting and parsing, date and time formatting and parsing, currency formatting, message formatting (ICU message format pattern), and plural support.