How to display special format date

I need help. I want to display a result like:
A user enters the date she gave birth. I would like to see, for example, today, "you gave birth 2 years, 5 months and 2 days ago, how do you integrate this calculation and display in my app?


I believe you could use the breakdowns provided by the format-date() function for the two dates to help provide this, although this is difficult in general due to the vagueness of “month” time windows.