Babies (little guys) need to eat everyday and 3-4 times a day but adults can go every other day.
We feed ours adults (now) everyday for most unless they are brumating. But when we only had a few bearded dragons (in the begiining - ages ago) and weren't worried about them breeding, we fed them every other day (Mondays, Wednesdays and Fridays and weekends off) and most of the time we would be away for the weekend.
On weekends we would leave the lights out and for them it would be an overcast (Clowdy - Sunless weekend) and they would most likely sleep almost all weekend. When we got home on Sunday we would turn on their lights and hand feed them some fruit, some quality time with our dragons, with the lights remaining on for at least 2 hours after their feeding.
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Tom and Jackie Vandiver 
Bearded Dragons and More!