Sorry I am even confusing myself now - Basically your formula is great however I want to alter the amount of days increased per selection so for 1 week i want it to be the start date plus 6 and a month is counted as 28 days in the gym so i need to alter this and also when i select year it does not change the expiry date by 1 year instead just by 1 month. Could you please explain to me how to make these changes to the formula, is this made using macros or just formula?