Get User $Locale in Lightning Component

The $Locale global value provider returns information about the current user’s preferred locale.

Use $Locale in Lightning Component:

<aura:component  implements="flexipage:availableForAllPageTypes,force:appHostable">
    Language : {!$Locale.language}
    Timezone : {!$Locale.timezone}
    Country : {!$Locale.country}
    Currency : {!$Locale.currency}
</aura:component>

Use $Locale in Lightning JS Controller:

doInit : function(component, event, helper) {
    var locale = $A.get("$Locale.country");
    alert("Your Country " + locale);
},