Recurring jobs do not have an official option to be able to scheduled for twice a month. They can be scheduled fortnightly, but this will occasionally cause the recurring job to be scheduled 3 times a month.
A way to ensure that the jobs are scheduled for twice a month without going over, is to schedule the Recurring Profile to schedule the jobs with 15 to 16 day intervals. This will account for the 30 to 31 days that most months have. However, on the rare occasion a month may have 3 jobs, which may require manually moving a job. But it will occur much less frequently than scheduling fortnightly.