I want to display the duration of a command in my script. Depeding the duration I want somethng like this: `12 minutes 04 seconds` or `01 hours 15 minutes 02 seconds`. Always with a leading zero.

I tried different things I found [here](https://stackoverflow.com/questions/8903239/how-to-calculate-time-difference-in-bash-script), but didn't get the result.

BTW: that's my first try in the bash.