Gold For Every Date

Once Mandar forgot his mother in law's birthday. Obviously, as a universal rule, he got the punishment. His wife ordered, I want you to present gold weighing equal to date of day on which my mother would surprise visit to our home.

Now Mandar went to jeweler & ordered only 5 gold coins of different weights. What are the weights of those gold coins?

This is how he does! 

Gold For Every Date Designed Smartly

What was that intellectual puzzle? 

On whichever date she visits, he just presents those coins under which 1 is written. For example, if she visits on 25, he would give her coins weighing 16,8 & 1. And if she visits on 18, he would present her coins weighing 16 & 2! Great use of binary number system!