"First Class complimentary meal times: Flights 900-1500 miles breakfast is served on flights departing between 5–9:45. Lunch is served on flights departing between 9:46am–1:30pm and dinner is served on flights departing between 4–8pm."
from:
https://www.delta.com/traveling_chec....../dining.jsp
Meal service in FC is based on 1) length of flight and 2) time of day (and a few other arbitrary factors you'll discover the more you fly specific routes).
Your flight #2503 departed at 2:00 PM local time and flew 1129 miles.