This is essentially the goal of keeping money in your possession for longer. I.e. any day that money is in your OFFSET account, you have reduced your interest cost.
So if a credit card can ‘pick up the tab’ for any period of time e.g. 30 or 55 days interest free credit cards. That is 30 or 55 days that money has been able to sit in your offset account, reducing your interest cost. As opposed to your money being handed over to a shop or merchant, on the day you buy something. The ctritical part of this play is that you MUST pay the credit card balance on time, to avoid paying interest on the credit card.