Trainers looking for a Ghost and Flying-type Pokémon in Brilliant Diamond and Shining Pearl may be interested in tracking down Drifloon. It won't be easy, but it can definitely be worth it.
Players who want a Drifloon will need to head to the Valley Wind Facility, just off Route 205 near Floaroma Town. When you first arrive here, Team Galactic will do no good by trying to take over the power plant so that they have access to all the energy.
You'll need to get rid of them if you want to capture a Drifloon, so be sure to defeat them in battle. Now, this is where it gets even more awkward. Drifloon will only appear on Fridays in your local time, and Drifloon will not appear on the same day you lead Team Galactic out of town. So if you're playing the global launch, you'll need to get rid of Team Galaxy and then wait a week to try and get Drifloon.
The good news is that Drifloon will have a guaranteed position. On the Friday after you get rid of Team Galaxy, head to Valley Windworks and make your way to the building entrance. Here you will find a Drifloon next to the sign.
Make sure you actually catch him, not defeat him, because if you don't get him this time you have to wait another week. That's right, time travel joking around with the clock on your Switch won't work as well as you think. You will simply have to wait a week for the next one to show up in the same spot.