Calculate month & year in between two dates
 

I have to calculate gratuity of an employee. for that reasone I have to
calculate total month & year from the date of joining to leaving date of
employee. example -
A B C
1 Date of Joining Date of Leaving Total Month & Year
2 11/02/2003 28/11/2006
in C2 I have to use a formula to calculate month & year, if calculate month
is less than 6 month then it round up 1 year else zero. Is there any formula
about my quary. Thanks in advance