The Euro is available to trade 24 hours a day, five days a week – from 10pm (GMT) or 11pm (BST) on Sunday evening to 9pm or 10pm Friday night.
The best time of day to trade EUR will depend on which pairing you decide to focus on. As a rule, each pair will see the most movement when its sessions overlap. For example, the EUR/JPY pair would be more highly traded when both the European (London) and Tokyo forex sessions overlap.