Notice Period

Hi All, 

Can anyone advise what the last working day would be in the following situation? 

An employee has a 12 week notice period. They work a standard five day a week and work Monday to Friday. No bank holidays fall during this period.  What would the last working day be if  they resigned on Monday the 5th of June? The also have 18 days of annual leave to take.

Thanks in advance

Chris