PLEASE HELP


When exporting a spreadsheet out of SAP i am getting a mixture of date formats appearing in a column between US and UK so when i want to filter by that column and have the dates running oldest to newest, it will only pick up the UK dates. I have try to change the format of the US dates but can not seem to alter/edit them at all other than physically going and changing the date on all of them one by one.

Can anyone shed any light on this please?

PS its Excel 2007