Harry's Pensieve would be delivered in 18 months.
"What?"
"I know!" the shopkeep nodded enthusiastically, "I was surprised too. Anything less 'n three years is particularly good from this workshop. And it's being crafted by the master enchanter 'imself! This has turned into a very providential purchase for you, good sir. You couldn't get anything better for your galleons if you tried!"