You are not giving it the first time to run (the part where it says "Wait 'Date and Time'" in the middle).  So you are telling it to repeat after the first time, but not giving it the first time.  Something like this, will run after 7 days and then repeat every 7 days.

Also, you have it set so that it does not interrupt the task, which is fine, but you have the path leading back into the task, which is going to result in the tasks being duplicated each time the timer triggers.  So I recommend having that path feed into an End event instead.  Just make sure you are using the End Event (which ends this path, but not the full process) rather than the Terminate End Event or Error End Event.  It'll look something like this:

EDIT TO ADD: Also - you might be able to simplify things even more by using the "Reminder" functionality that is built in to the User Task iteself, rather than doing this Timer Catch Event at all.