Is there a way to set up time interval for swimming app?

When I create a poolswimming workout there is only one type of duration - distance. But is there a way to set up step duration in time?
For example I have planned workout like this

  1. 200 meters any style
  2. 30 minutes freestyle (doesn't matter how much distance it would be)
  3. 15 minutes of mixed swimming
  4. 10x100 meters freestyle
  5. etc

So how can I put 2nd and 3rd step in Garmin pool swimming workout?