The Golden Hour is a term used to in photography describe a period of time when during dusk or dawn when the sun is below the horizon when you have a clear sky. The light is diffuse with typically a golden hue. Some people describe this light as magical.
It is great when you get an opportunity to shoot is this sort of light. The feeling of a place changes in this light. Remember, amount of light is low, so you will probably have to boost your ISO or open up the lens or drop the shutter speed. This might be a good time to use a tripod.
Some people are obsessed with shooting is this sort of light. Personally, think you can get good photos in almost any kind of light. A lot of it depends upon the weather. Of course, take advantage of the light when you have it. Advanced planning can help. So can hiring a local guide like me to show you where to be when the light is good. (Photo by Paul Crouse / KyotoPhotoTours.com).