fix: fractional seconds not supported for iso dates (#894)

* support fractional seconds

* fix conversion

Author: henninghall

ios/RNDatePicker.mm

@@ -51,6 +51,7 @@ + (ComponentDescriptorProvider)componentDescriptorProvider
 NSDate* iso8601StringToNSDate(const std::string &iso8601String) {
     NSString *nsString = [NSString stringWithUTF8String:iso8601String.c_str()];
     NSISO8601DateFormatter *isoFormatter = [[NSISO8601DateFormatter alloc] init];
+    isoFormatter.formatOptions = NSISO8601DateFormatWithInternetDateTime | NSISO8601DateFormatWithFractionalSeconds;
     NSDate *date = [isoFormatter dateFromString:nsString];
     return date;
 }

src/DatePickerIOS.js

@@ -21,10 +21,10 @@ export const DatePickerIOS = (props) => {
     ...props,
     onChange,
     style: [styles.datePickerIOS, props.style],
-    date: props.date ? props.date.getTime() : undefined,
+    date: props.date ? props.date.toISOString() : undefined,
     locale: props.locale ? props.locale : undefined,
-    maximumDate: props.maximumDate ? props.maximumDate.getTime() : undefined,
-    minimumDate: props.minimumDate ? props.minimumDate.getTime() : undefined,
+    maximumDate: props.maximumDate ? props.maximumDate.toISOString() : undefined,
+    minimumDate: props.minimumDate ? props.minimumDate.toISOString() : undefined,
     theme: props.theme ? props.theme : 'auto',
   }