Answer:
Day 6.
Although Adam was not actually Adam before Eve was made. The original Hebrew Bible has a separate word for the human before Eve is made suggesting that there was a non-gendered 'human' which god then divided into a male and a female. This is discussed in Peter Vardy's 'The puzzle of S**' where he talks about how a lot of the bible was actually mistranslated from the original Hebrew.
The asterisks are there because WikiAnswer's doesn't like me using the copulation word.