"Days of notice" refers to the number of days you need to give the contractor before ending the contract. This is mutual; the contractor will have to give you the same days of notice before resigning. You can end the contract at any time before the end date as long as you provide the days of notice as agreed to in the contract.
The standard days of notice for termination is anywhere between 7 and 30 days. We have defaulted to 14 in the hiring flow. You can update this to any agreed value.