it's changed now thou, for the last few months a spouse visa should be valid for 27 months not 24 months, so the problem that some people on here have, that is they came to the uk more than 28 days after the start date of their visa, which means they cannot be in the uk for the required 23 months which enables them to apply for ilr, becuase their visa has expired already, it should not happen any more, as your visa should now be valid for 27 months, giving you nearly 4 months to get to the uk
, not the 28 days,, so it should be a problem of the past soon