Payments made to your credit card before 10pm are processed overnight on each business day. If the payment is made after 10pm, it will be processed at the end of the next business day, appearing in your account the following morning.

If you make a payment using Westpac Online Banking (a funds transfer), the date you did the transaction will be the date that the payment is applied. So if you make your payment over the weekend, the effective date of your payment will be the day you did the transfer, although it won't show on your statement until after the next business day.