Invitation wording- Shower

My bridal shower is January 23. On my invite it will say 'the twenty-third of January.' Is that correct or should I delete the '-' and make it 'the twenty third of January.'

Also, do I need to put 2010? I'm sending the invites out in December. I would think that common sense would lead one to just assume that it's for next month and not 13 months later!

Oh, and RSVP date. Is 2 weeks before the shower good?

TIA!!

you should hyphinate the number. you dont have to write 2010 but its traditional.
good luck and congrats!