This is a little utility which I am using to format my timesheets.
I'm using toggl time tracker to keep records of hours spent working for my client.
On the first days of each month, I download a 'Detailed report' from toggl, and convert it to the format my client accepts.
Report.exe /Users/user/Downloads/Toggl_time_entries_2017-06-01_to_2017-06-30.csv /Users/user/Desktop
That would produce a report named as June 2017.csv (previous month)