I’ll be buying the tickets for my flight to Seattle and Kaleidoscope 14 some time tomorrow. The cut-off date on my credit card bill is today, so if I get the tickets tomorrow I won’t have to pay for them until the end of March.
When you know you have to pay it’s worth thinking about when you have to pay. It’s a principle that works in Oracle databases, too.
On the flip-side – sometimes you don’t realise that the clever thing you’ve done now is going to make someone else pay later.