Mix together the lemon zest, lemon juice, orange zest, orange juice, mustard, honey, red pepper flakes, garlic, and salt.
In a large ziploc bag, place in the chicken thighs, carrots, onions, dates and add the marinade. Massage the bag to ensure the chicken thighs are evenly coated. Then marinade the chicken for at least 40 minutes. I marinaded mine overnight.
Heat the oven to 425 and transfer everything from the ziploc bag on to the sheet pan with the chicken thighs' skin facing up.
Bake for 30 minutes but keep an eye on it to make sure the carrots and onions close to the sides of the pan don't burn.
Optional: serve with a side of rice or noodles to complete the meal prep!