As Will said earlier in this thread, Currently there is no support for recurring workflow tasks, i.e: Daily Workflow firing
There would be ways to do a workaround for this, such as having your cron job run once a day, but this may not be ideal.
You could also possibly create a True/False checkbox field that stores if a record has been has fired upon today, but you would manually need to change it back to False each day.
Another possibility may be to add an Action to the workflow to Modify Record, and increase a Task’s “Date Modified” by 24 hours so that it fits inside the Conditions again and shouldn’t fire for another 24 hours. However, this too may not be ideal as the Data modified would be constantly changed.