qualifying period for ILR is 2 years in the UK - upto 28 days
not 28 days b4 your visa expires
"You should use application form SET(M) if you:
already have temporary permission to stay in the United Kingdom (limited leave to remain) as the husband, wife, civil partner, or unmarried or same-sex partner of a permanent resident;
have lived here for two years in this category; and
are still married or in a civil partnership and plan to live together.
If you delayed your journey to the United Kingdom by weeks or months from the date you received your visa, your visa will run out before the end of your two-year qualifying period and you may need to apply to extend your visa, using application form FLR(M) (see Applying to extend your visa for more information on doing this).
You must not send us your application more than 28 days before the end of your two-year qualifying period If you do, we may refuse your application with no refund of the fee. However, you must make your application before your current permission to stay in the United Kingdom expires.
You must be in the United Kingdom to apply. For information on obtaining initial permission to come to the United Kingdom in this category, see Can I live in the United Kingdom? To extend your temporary permission to stay in this category, see Applying to extend your visa.'
http://www.bia.homeoffice.gov.uk/ukr...ionformset(m)/