When a person forgets time and is completely focused on what he is doing at the moment and has become one with the activity – then the person is in flow. Many know this condition from their hobbies and it is possible to reach the same state in your work life, which will lead to a feeling of happiness.
The precondition for flow is that one is dedicated to a task with the exactly correct degree of difficulty: the task should not demand too little and at the same time be manageable. Some effort should be part of it – but it must not lead to frustration. It is easier to enter the flow if there is no time limit for the task. Those who constantly check the time because they have to go to show up at a meeting one hour later will not reach this state of flow.
It does not mean that flow will automatically lead to overtime, but the person should be in control about his time management. Another important aspect is undisturbed concentration. Telephone calls, emails, conversations with colleagues – they all disturb the work flow and destroy the sense of happiness. If one wishes to experience flow seriously, one should eliminate sources of disturbance – or at least close the email program temporarily.