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UVB bulb is one of the most important parts of your beardie's home. Regardless of how nice your weather is, you'll want to pick up a ReptiSun 10.0 (tube) bulb to keep on hand; you never know when unforeseen circumstances will keep you from getting your pet outside.
More than 30 minutes of natural sunlight will be great for a beardie. Some people keep their beardies outside for an hour, some keep them out all day when weather permits. Just be sure to provide adequate shelter if you plan to keep him out for any extended period of time so he's able to hide out in the shade to regulate his body temperature. Also, take whatever measures you need to protect him from birds and other predators, outdoor pesticides and chemicals, and all that other common-sense stuff.