Allay should spawn at nighttime, giving a reason to travel at night

Currently, there's no reason to explore Minecraft's nighttime (other than to get phantom membranes). It's easy to get night mob drops from mob grinders. Many players like me never seem to venture out at night, there's just no good reason. Having a passive helpful mob that uniquely spawns at night will be a great idea. Imagine these colorful Allays flying through the forests at night, they'll look very good.