However, it is immigration -- passport control --- that can take time. There is no immigration in Canada or Turkey if it is just a connection. Connection time at Athens airport. 2 hours is sufficient.
No matter which terminal you arrive at, Athens airport is a very easy airport to navigate with signs in both Greek and English, friendly English speaking staff and a very clear layout.
No, it is not enough. If you have to switch from one plane to another, you should have at least two hours. Not only for you, but also for your luggage. If you have only one one hour, maybe you will be able to catch the next plane, but maybe your luggage will not make it!
Expect 15-20 minutes max unless you're unlucky. However since you fly with the luggage, this might take a while, and you can take overall up to 40 minutes before you leave the customs.
How strict is Greece with liquids? Bottles with liquids/aerosols/gels are placed in a closed clear plastic package which volume does not exceed 1 litre. The size of the package must be 20.5 cm x 20.5 cm, or 25 cm x 15 cm or of equivalent size. Only one package of liquids/aerosols/gels per passenger may be carried.
How long is customs in Athens? As a general rule 1hr is usually more than enough to clear immigration and get your bags unless there's a huge number of inbounds at the same time. I'd say you're OK with 2 hours between flights everything by going well with more time obviously better.
Carry your passport or some form of photo identification at all times. Police may detain you for questioning if you do not have proper identification with you.
What is a good connection time? Travel advisers say there's a lot to take into account when booking connecting flights, but a general rule of thumb is 60-90 minutes between domestic flights and at least two to three hours for international itineraries.
In brief, the Airport of Athens is a huge international airport that receives hundreds of domestic and international flights all year round. It is located around 30 km from the center of Athens and its up-to-date premises can accommodate all travelers' needs.
You could make connection for less than 40min time between the flights if they are Schengen-Schengen or NonShcengen-NonSchengen. You need at least 1h if your flights are NonSchengen-Schengen or vice versa, because you have to exit the zone and do all the checks as passangers from A to B (flying directly) does.
If you are talking about a connecting flight on the same day with the same confirmation number, you only have to check in before the first flight. You will get boarding passes for both flights. If they are booked as separate flights (meaning they are not a connection) you have to check in for each individually.
According to European Regulations, all travelers entering or leaving the European Union with more than €10.000, in cash, must declare the amount to Customs. Customs controls at Greek points of entry distinguish between goods bought within the EU and outside the EU.