Adding events to my native calendar

Hey Community,

We are currently building a fitness application which allows a user to either create fitness programs or purchase them. They can select the date of their choice and select single/multiple time slots to schedule the same.

The requirement is that dates and slots should be copied to the native calendar however, the challenge is I am able to see all timeslots for one date and not for the rest. Could you please provide suggestions as to how the native calendar can be manipulated using xcode?

Adding events to my native calendar
 
 
Q