Changing timezone do not produce effect

[wysman]

Hi,

I use the setDateTimeFormat function to update the dateTimeFormats definitions to allow users to select their preferred timezone or change the timezone based on their current activity. The following code is an simplified extract of our code to flip/flop timezone between Europe/Paris to UTC.

  const locales = i18n.availableLocales;
  locales.forEach((locale) => {
    let formats = i18n.getDateTimeFormat(locale)
    Object.keys(formats).forEach((index) => {
      if (formats[index].timeZone === 'UTC') {
        formats[index].timeZone = 'Europe/Paris'
      } else {
        formats[index].timeZone = 'UTC'
      }
    });
    i18n.setDateTimeFormat(locale, formats);
  });

This code allows to change the dateTimeFormat configuration but do not have any effect on date rendering. By adding the following tricks, the timeZone is correctly used during rendering.

  // Clear some cache ???
  i18n._dateTimeFormatters = {}

I think vue-i18n must clear clean its internal cache when the configuration change.
Also, it's can be nice to have an overall timezone setting too.

Best regards,

[wysman]

@kazupon Thanks for the quick fix !