In a bowl, whisk together lemon juice, lemon zest, minced garlic, olive oil, dried thyme, dried rosemary, salt, and pepper.
Place chicken breasts in a resealable plastic bag or shallow dish. Pour marinade over chicken, turning to coat evenly. Marinate in the refrigerator for at least 30 minutes, or up to 4 hours.
Preheat grill to medium-high heat. Grill chicken breasts for 6-7 minutes per side, or until fully cooked through and no longer pink in the center.
Remove chicken from grill and let rest for a few minutes.
Slice chicken breasts diagonally and sprinkle with chopped parsley before serving.