102 inches is legal, but that must include your side mirrors too. Wide body motorhomes have the body being 102 inches and the mirrors can stick out at least another foot on each side. How far you can stray from the interstate varies by state.
Sometimes, you need to know exactly how many years, months and days between two dates, in this situation, the following long formula may help you. 1. Years,  & DATEDIF(B1,B2,YM) &  Months,  & DATEDIF(B1,B2,MD) &  Days. Note: In the above formula, B1 indicates the start date and B2 stands for the end date, you can modify them as you need.
An easier way in figuring out due dates is to take the first day of your last period, count backward 3 months, add 7 days, and add an entire year. This is called Naegele's Rule. (Alternatively, to get the same result, you can take your LMP, add 1 week, and add 9 months.). 4. Choose other methods to calculate your due date if you cannot remember the date of your LMP or have irregular periods.