on Air canada website, it says free coffee and tea. Can you have free beverages at anytime when requested?

They have a system. Basically, they start with the food service, and then tea and coffee afterwards. It is possible to request more after that time, but, only to a certain point. It is not like a restaurant when you can just request stuff. The carts they use block the isles completely, so, they try to be fast when they are serving.

Oh, pop, and juice are also offered, not just tea and coffee.

And, if you do wish to buy anything (food, or booze), they only take charge cards. They will not take cash. I'm not sure how legal that is, but, that's the way it was on the flights I've taken this year with Air Canada.

When I have been on overseas flights to London and Paris, they both left in the evening and arrived the next morning. In both cases, a meal was served in the evening after we had reached cruising altitude, along with your choice of hot or cold beverages. Then they would turn down the lights, and you could lay back to try to sleep, watch a movie, listen to music, or whatever.

Then they would turn on the lights the next morning toward the end of the flight, offer everyone breakfast and again hot or cold beverages, about an hour before your scheduled landing.

Once the carts are stowed away, usually so is the coffee and tea. However, you can ask one of the stewards or stewardesses and if it is not too much trouble, they may be able to get some for you depending on how the aircraft is designed. On most aircraft, I believe the food and drinks are stored in a special kitchen area on a floor below the passenger area, while others have a fridge/microwave in a little alcove near the front of the plane.

u have to pay for dinner and drinks soda pop,juices,tea and coffee are free u can ask any time for a drink.