iOS app. Looking for Weeks picker!

I'm working on iOS app for medical doctors that lets them find a job.

Doctors work part time and could change several hospitals for a year. Hospitals hire them when they need a specific practitioner. Doctors decide what period they want to work.

To start searching for jobs doctor has to provide his/her availability (in week numbers, it's common for them at the moment).

For example, doctor could say s/he's available for work through weeks 10-15 and, also, on weeks 17, 21.

The major requirements:

  • user can pick the weeks range or a single week number
  • there is an option to have ranges and single numbers at the same time
  • the large part of the audience is senior people 55+ so I would like to stay away from patterns and gestures for 'power users'

I struggle to find the solution for this. Do you have any ideas of how it could be designed?

I will appreciate any ideas, insights or suggestions.

Thanks