I don't know where this six days is coming from, but to go back to the 14 days:
- You need to ensure you give the right period for rectification before taking the next step. You could be penalised for further action you take if you don't give them the required time allowance to rectify. This can range from the furthe action being invalidated down to losing interest/costs.
- As Tim stated, the 14 days appear to be 14 business days. As you've stated: "Unless expressly stated otherwise, where any notice is to be given or any other act matter or thing is to be done under any provision of this contract in a stated period of days, the following days shall not be counted: Saturday, Sundays or Public Holidays." So, start counting the 14 days from the date you sent the notice (not counting the day that you sent it) and ignore any day which is a Saturday, Sunday or Public Holiday. You'll find the date will be just under three weeks out from when you sent the notice (unless Melbourne Cup Day is one of the days - then it will be three weeks).