When flying out of EWR on CO on a morning flight before 10am at least 90 minutes and up to 180 minutes if flying domestic or 120-180 international. I know it sounds like alot and others will post that they get there 35 minutes before flight time but I fly alot, almost always from EWR and in the morning it is has taken over 30 minutes just to drive up to the terminal from the airport road at 6-7am and it has taken over 1 hour to get luggage checked in. Sure some days it is not as bad, but most of the time it is a zoo in the morning. After 10am 60 minutes is enough domestic and 90 international. It takes me about 1 hour to get to EWR or 90 minutes during rush hour. So when I have an early flight, say 8:30am I leave at 5:45am, get to the airport about 7:15am and hope to be checked in by 7:30am. This way I have a half hour at the Presidents club before boarding.