The bulbs that I ordered in August arrived last week. I don't remember whether I specified this late planting date or the vendor decided it on their own. I was lucky to have a dry day on which to dig holes in Awful Heavy Clay to get them planted. I amended the soil with compost I'd harvested over the summer and a little bulb food.
By the end of the afternoon I'd planted 75 grape hyacinth bulbs and 30 daffodil bulbs, about my limit for one day's work. The weather gods then smiled on my efforts by providing some very nice showers to get the bulbs watered in.