List gaps between smallest and the biggest time interval

[ammusk354]

I had an php interview question and I am curious about the solution, maybe you can help me.

The problem sound like that :

There are many time intervals in this format 'ZZ-LL-AAAA'. I want to know if there are gaps between the smallest date and the biggest date from all the intervals.
List the gaps.

some example :

1) 01.01.2000 - 31.01.2000
2) 01.03.2000 - 31.03.2000
3) 15.01.2000 - 15.02.2000
gaps it will be 16.02.2000 - 28.02.2000 (or 29, if is bisect year)