You can already add your own periods by clicking the 
icon, see here.
As for the order, it’s almost like you wrote - from what I see, only years are not ordered, which I was pretty sure actually should be ordered, so seems more like a bug.
You can already add your own periods by clicking the icon, see here.
As for the order, it’s almost like you wrote - from what I see, only years are not ordered, which I was pretty sure actually should be ordered, so seems more like a bug.