Another health insurance company has extended its payment deadline for people who signed up for coverage last month.  Humana spokeswoman Cathryn Donaldson says customers have until January 31^st to make their first monthly payment.  She says the goal is a smooth transition for consumers with plans effective January 1^st.  Earlier, Blue Cross Blue Shield of Illinois extended its deadline to January 30^th.  Other insurers, however, say Friday remains the deadline to pay for customers who enrolled last month for coverage under the Affordable Care Act.  Plans offered by Aetna, Coventry, Health Alliance and Land of Lincoln Health are sticking with the Friday deadline for people with policies effective January 1^st.  President Barack Obama’s health care law requires most Americans to sign up for coverage by March 31^st.