This is required to be a CLI application implemented in node.js using only primitives, built-in language functions and no external npm dependencies. You should build the application so it accepts input from stdin. Please do guide the user through the steps required to use your application, and do validate your input. A complete solution should include your source code, documentation and unit tests. You can upload the source code publicly to Github and share the link with us via email.

You need to calculate the distance in whole days between two dates, counting only the days in between those dates, i.e. 01/01/2001 to 03/01/2001 yields “1”. The valid date range is between 01/01/1900 and 31/12/2999, all other dates should be rejected. When testing your solution, use the following sample data to demonstrate your code works:
a) 2/6/1983 to 22/6/1983 19 days. b) 4/7/1984 to 25/12/1984 173 days.

python calculate.py