The recommended arrival time for passengers at the airport can vary depending on several factors such as the airport, time of day, the airline's policies, and the destination. While three hours is a general guideline for international flights, here are some considerations for different types of flights:

1. International Flights: Arriving at least 3 hours before the scheduled departure time is advisable. This allows time for check-in procedures, security checks, immigration/customs processes, and unforeseen delays.

2. Domestic Flights: Arriving 1.5 to 2 hours before departure is usually sufficient. However, this can vary based on the airport's size, security lines, and peak travel times.

3. Peak Travel Periods: During busy travel seasons (holidays, weekends, and peak vacation times), it's wise to add extra time to your arrival, perhaps an additional 30 minutes to an hour, to account for potential crowds and longer wait times.

4. Special Circumstances: If you're unfamiliar with the airport, traveling with special needs, or have connecting flights, arriving earlier than the general recommendation can reduce stress and accommodate unexpected situations.

Always check with the airline or airport for any specific guidelines or changes in recommended arrival times, as they might have updated information or policies. Additionally, factors like traffic conditions en route to the airport should also be considered when planning your arrival time.