Editing Date/Time format in "Accept as a solution reminder" email

Hi the standard email for "accept as Solution reminder" has the date formatted like this

"Date: Fri May 10 17:41:13 CEST 2013"

Using this text key "Date:

${thread.topicMessage.postDate}"

Can anyone point me at other text keys that I could use to format the date like this?

"10-06-2013 14:04"

Thanks