In cell C1 use the formula =INT(B1-A1) to get the days. Then you have to get the remaining hours, which is the formula =MOD(B1-A1,INT(B1-A1)) and represents the remaining time. So in cell D2 enter the formula =HOUR(MOD(B1-A1,INT(B1-A1))). In cell E2 enter the formula =MINUTE(MOD(B1-A1,INT(B1-A1))).
You can opt out of Medicare Part B and in some situations you should opt out. Most people are automatically enrolled in Medicare Part A and Part B when they turn age 65. And most receive Part B at no charge. Medicare Part B is optional and you may not need the coverage if you have a group health plan.
Most people go on Medicare at age 65. You cannot get on Medicare at a younger age unless you meet the guidelines for qualification while having Lou Gherig's Disease or End Stage Renal Disease, or if you have been receiving Social Security Disability benefits for at least two years.