I´d like to see an end date for recurring tasks, alternatively a possibility to define a number, how often a task is to be repeated. Example: A task is to be carried out every friday, but only during daylight saving time (april-october).

This would definitely be useful. Another use case would be Take medicine everyday, but only for 7 days or task should end after 7 recurrences 

Yes, a recurrence counter would be a great inclusion.

Like Ram R, I want to set a task to take medicine at the same time each day, but only for the prescribed time period. The only way I can currently do this is to set a daily recurring task and then a separate task for the end date "Stop taking the medicine today".

Adding to the request, would love to have an "end date" for repeating tasks. With our farm, everything is seasonal, and many repeating tasks only go on for so many days or weeks. Thanks!