Highlight the column you want for day-month in the top line of your sheet i.e. 'C'
Right click and go 'Format cells' then the 'number' tag
Choose 'Custom' then scroll down till you see 'dd-mmm' and pick it.
Once you have all the months enterered you only have to type say '2 [space] F' to get 02-Feb in the column.
If you 'freeze' the top line (the column descriptions you have entered) and then select all the columns and 'custom sort' you can put everything in order by the columns you want ie. Sort by Year, then date then parish etc. Don't forget though when sorting the whole sheet you have selected all columns and tick the 'My data has headers' box (the frozen description line). If you forget a column all the lines will fail to line up and you work will be wasted. Perhaps get in the habit of saving a copy every so often that you can go back to as it is easily done!