Dear JeteMC and HSV, Thank you so much!

Now for the bonus (sorry for being cheeky). I also have two other columns of data - Hour and AM/PM.
e.g.
HOUR AM/PM
1 AM
1 PM
2 AM

Is there a way of getting excel to recognise these two columns as a time category or does it need to be linked to the date fields that you just helped me with?

Thanks

Peter