Copy a row record to a sheet based on the date entered in to a cell

Hi All,
I have scoured lots of forums and still cannot get the code for this to work.
I have a workbook with 13 sheets, sheet 1 is "Main Data" the other twelve are the months of the year Jan to Dec
On the Main Data sheet contains thousands of rows/records there are 3 columns where the users can enter dates, column C "Inception" column D "First response" and column E "Future Meeting".

What I need is that if any user enters a date in to any of the 3 columns then that row/record is copied and the values pasted to the next empty row on the relative month sheet, the copy and paste should happen once the user presses the enter button on the keyboard after entering a date.

Looking forward to any answers

Gary