Employees - little interview task for beginners

Link to hosted project: here

Write an application that finds the couple of employees who have worked together on common projects for the longest time
"DateTo" also accepts a value of "NULL" (which is equivalent to "today")
The data can be submitted from a text file
The program can be run without the need to make any changes to the code, ie. after "checking" the code and importing it into the IDE
The program can start and show the result in the console
To comply with the "code convention", depending on the language in which the program is developed
Solution of the problem to be put in github
To be done within a day

To make a UI where the user can select a file from the file system and after selecting the file to see the result in the "datagrid" with the following columns: Employee ID #1, Employee ID #2, Project ID, Days worked
To support more than one or all (for "all" you'll get many points) date formats

Name		Name	Last commit message	Last commit date
Latest commit History 13 Commits
src		src
README.md		README.md
index.html		index.html