dates – Time field that can be used as both a Duration Field and a Start Time Field

I’m making a recipe app.

When adding an ingredient, I need a field that can be used to specify the time that the ingredient must be added, OR the duration it must cook.

For example, I can add onions after 10 minutes since the start of the cook, OR I can caramelize the onions FOR 10 minutes

Currently, I can only enter the time that the ingredient must be added:
addition time field

I need to add some sort of toggle so that the user can chose if this time is a duration or an addition time

Thank you.