usually FLR is valid for 2yrs, or sometimes they will make it shorter.
there is no set number of days you need to be in the UK to apply for ILR, but the uk is suppose to be your home.
if work has posted you to another country then the case worker may well accept that your wife has a valid reason for being out of the UK a year and still grant her ILR.but phone UKBA and ask for their advice.. you might have to apply for FLR still
but it will probably delay her applying for citizenship.
