Issue with Date format in Excel 2003

Hello All

This is my first post in this Forum.

Issue:- I have a file with 'Open Time' as a header and underneath 475 entries of "date & time" with various date formats like dd/mm/yyyy HH:MM:ss
mm/dd/yyyy hh:mm:ss and so on. There are few items that i have managed to change the Date to "Month,year" ie. January-11 but there are many items that even does not get edit and changed to "month-Year" format.


Aid: I'm attaching a sample of that file so that you can have a look and you can work.

Looking for solution : I'm looking for a solution, to have attached file date and time in two different columns- Time should remain same in that format but Date should appear like -dd/mm/yyyy and when copy and paste in other column and changing format should appear like January-12 (as an example)