Please ensure before you activate your new debit card that all recurring payments, bills and/or checks are fully paid out of the old account. Once you activate your card it will trigger the funds to transfer to your new account. Since your balance will be at $0, this will cause your payments or checks to be rejected in the old account.
If your card is activated before 8 am PT on a business day, your old card is deactivated that same morning, around 8 am PT.
If your card is activated after 8 am PT on a business day or on a non-business day, your old card is not immediately deactivated; it is deactivated around 8 am PT the following business day. The wire to move your funds from your old account to the new account also happens the following business day. This means that if you activate your new card on a Friday at 3 pm PT, for example, you can still use your old card over the weekend.