When somebody is giving notice in months the ‘corresponding date’ rule from the case of Dodds v Walker applies. This means that the notice period will end on the corresponding date in the relevant month. So, three months’ notice given on the 6th July will expire on 6th October making the 6th October the last day of employment.
If somebody is giving a week’s notice and they give notice on Monday 1st October, then their notice is going to expire on Monday 8th October, and the 8th October will be the last date that they work. This is because notice is actually calculated from the day after the one on which the employee gives notice. In the 1986 case of West v Kneels Ltd the reason behind this was explained as follows “to say that there’s a day’s notice where an employee has given notice 30-seconds before the end of the working day would be an abuse of the English language and contrary to good industrial practice”. The day on which the notice is given is discounted and the employee commences working out their notice the next day. This is exactly the same when the employer is giving notice to the employee.