I just noticed that on the forms you download it has the following text:

"A marriage is proposed to be solemnised between me and (name and surname of partner) of (usual address) a (nationality of partner) National at (place of marriage) on (date of marriage)"

This indicates you need to know the date and place of marriage.

This was a concern for us as we were not sure of the actual date as we are going to set it around the 24th of November but wanted to make allowance to ensure we have the marriage licence.

I called the Embassy for clarification. They said on the phone it's ok not to put the actual date of the wedding as the document is valid for 6 months. I have therefore put "in November 2014" instead.

I thought this might help others.