When flying from Fayetteville to Amritsar, the time of day you decide to fly out makes little to no difference towards the overall price you’ll pay on tickets.
These are just IATA (International Air Transport Association) codes. They are used in aviation to identify and differentiate airports. That’s why a Fayetteville Northwest Arkansas Airport to Amritsar Sri Guru Ram Dass Jee Intl Airport flight would often be abbreviated as a XNA to ATQ flight.