Rango de fechas: this field cannot hold more than 1 values when I try to sync content to a node with a date range field

I'm working with Feeds to sync content from a JsonAPI resource.

Everything works fine except the date range field.

I get dates like this from the source:

 0 => "2023-10-27T00:00:00" 1 => "2023-10-28T00:00:00" 2 => "2023-10-29T00:00:00"

And I have try to return:

return   ['value' => reset($source_data),'end_value' => end($source_data),  ];

Also

return reset($source_data).'/'.end($source_data);

But i get always the same error.

This is my mapper configuration: