convert a text date into a proper date

I have a column of dates in thie format " January 5 03:09:36 2009" which i need to convert into a proper excel date that i can do further calculations on (adding up things, graphs etc based on dates).

Note the space before the month name. I thought about doing a left(cell,xx) to get it but that isnt going to work with the space infront and the variable length of month names.

I do not necessarily need the time included, it may be useful at some point if its easy to keep it as part of the data, if not i can live without it.

Thanks