On hearing that Day Zero just got pushed back a couple of months, the casual news consumer might be forgiven for confusing this with a bulletin from the Doomsday Clock scientists who predict the likelihood of worldwide nuclear devastation. But no, that metaphorical clock is still set at two minutes to midnight. Day Zero is the coming time when Cape Town, South Africa will essentially run out of municipal water for its 4 million residents — and for the visitors, too, who have long flocked to the beautiful, cosmopolitan city with a Mediterranean climate startlingly like our own.