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.
To add a given number of years to a date, you can use the EDATE function. How this formula works. The EDATE function is fully automatic. Simply supply a valid date and a number of months and EDATE will return a new date. To subtract months from a date, supply a negative value. Adding years.