Per your signed membership agreement, a 30-day notice to cancel your membership is required.
30-Day Notice Examples:
Cancel Jan 1 – Membership would end Jan 31 (30-day notice puts cancelation date to the end of Janaury and prior to the billing for February)
Cancel Jan 5-Jan 31– Membership would end February 28 (30-day notice puts cancelation date past the billing for February so member will also pay for the full month of February).