I have a stupid question


In the end I decided to ask for help from experts! Gentlemen, of course!

I'm trying to do simple timetable operations, not dependent on fully dates. Only timetables. Simple stuff (in natural language!).
Example:
What time is the 6:30 less than a minute? -----> 6:29
And the 23 and 58 less a minute? -------> 23:57
And the 23 and 59 plus two minutes? ------> 00:01
And the 18:35 plus 37 minutes? --------> ??? I need LC function!!!

I tried to use DateFormat function, but I do not understand the method without using a specific day.
I know someone is now laughing !!!! Let me also laugh at me!




Thanks to all those who want to give me a hand!
Mariasole
(='.'=)