I like to take babies outside for some sun for about an hour 4 or 5 times a week. They can get the needed UV with two 20 minute sunning sessions a week, but more opportunity to bask is better. My general rule is an hour of sunshine per inch of tortoise for babies. In your climate, and mine too, we really don't need indoor UV bulbs, unless we just want them for lighting up the enclosure nicely. A heat bulb for basking is all you'll need. Don't use "spot" bulbs for this purpose. Use regular round bulbs or floods from the hard ware store. I use 65 watt floods and I adjust the height to get the correct basking temperature under them.
I typed this up for russians, but care for DTs is identical. I feed some grass to DTs, but not to russians. That is about the only difference.
http://www.tortoiseforum.org/threads/russian-tortoise-care-sheet.80698/
http://www.tortoiseforum.org/threads/beginner-mistakes.45180/
Be aware that most of the care info out in the world for this species is wrong and will result in a dead baby. You are off to a good start. I would double the amount of substrate, and then add a humid hide instead of the flower pot. Soak this baby every day. Get a couple of 4" terra cotta saucers and sink them into the substrate. One for water and one for food. Get bigger saucers as he grows.
Please feel free to question all of this. No one will be offended.
