Templater: Creating a note which updates itself after edits

What I’m trying to do

I am using Obsidian planner OG and Templater. What I am trying to do is to create a template that serves as a plan for my day.
It looks like this:

Day Planner

  • XX:XX Plan the day
  • XX:XX+15minutes First task
  • XX:XX+45minutes Second task

In the above XX:XX is the time I start my day and I want to automatically update the rest. For example if I replaced XX:XX with 09:00 then my plan of the day would look like this:

Day Planner

  • 09:00 Plan the day
  • 09:15 First task
  • 10:00 Second task

Note that XX:XX should be replaced in the actual note and not in the template itself.
Essentially XX:XX should serve as a placeholder for a time and the rest of the plan should be updated automatically after XX:XX is replaced.

Things I have tried

From the thread Insert current time incremented by amount I am able to increase a time within the template by a given amount.