mandiebraxton already answered that, your passport need to be valid for at least 6 months and concerning time giving to fly depend on your 'medical' even though they always state it that your visa is valid until the expiration of your medical or your passport, whichever comes first but don't get it wrong if your passport will expire in January they will not issue the visa, it's better you get your passport renew and the way l see things maybe they will request for another medical because yours expired February 2015, l hope you have more understanding about the whole stuff now, l wish you good luck, God bless.