Hey @Soufiane_Ghzal 
- I did a bit of digging into this on my end and from what I can tell looking at the Props here, it doesn’t seem like it’s possible to handle localization externally:
https://polaris.shopify.com/components/selection-and-input/date-picker#props
Localization is handled on our end by the Date Picker component itself though (more info here in the code if you’re interested))
Hope this helps - let me know if I can clarify anything on our end here 