Your hat is lovely, and quite the nice example of an early to mid 1950s evening hat. That style was popular from the very early 1950s (actually started in the very late 1940s), and continued to be worn all through most of the 1950s. I would place yours somewhere around 1955. While the style could be a few years earlier than that, the Hodge label you show is more common on mid and later 1950s hats. I do not think it is much later than 1955-1956.
Hodge is one my favorite milliners, and it was nice to see your hat.