Date formatting in React Native

I try to format a date time value according to device settings. Whatever I change on the simulator settings or in xCode scheme, I always get US format with date.toLocaleDateString()

So I tried different librairies (moment, react-native-localize, ...) but same, always get US format.

So I tried to set Locale directly with this code :

  const date = new Date(Date.UTC(2019, 11, 26, 14, 5, 0))
  const options = {
     dateStyle: 'medium',
     timeStyle: 'short',
  }
  console.log(date.toLocaleDateString('en-US', options))               // Dec 26, 2019, 3:05 PM
  console.log(date.toLocaleDateString('fr-FR', options))               // Dec 26, 2019, 3:05 PM
  console.log(new Intl.DateTimeFormat('en-US', options).format(date))  // Dec 26, 2019, 3:05 PM
  console.log(new Intl.DateTimeFormat('fr-FR', options).format(date))  // Dec 26, 2019, 3:05 PM

And I still get same results !

What can I do to display my date in other Locale than 'en-US' ?

I don't want to hardcore the format by myself ("DD/MM/YYY HH:mm"), I want to use a Locale I set or better the device's one.

Thanks for advice