Quintessentially Summer..?

... Days like this; sunglasses bright, bees humming around the roses and butterflies flittering, remind me of the Jim Croce song, 'Time in a Bottle'.

I shall try and add an extra, having failed every other time I've ever tried :-)
It's a butterfly or moth (moth I suspect) and it's one I haven't been able to identify. (Probably because it's in the index under, 'I can't believe you don't know what THIS is, it's so common we didn't bother putting it in the book').