mm-dd-yy, dd-mm-yy or yyyy-mm-dd?

Vitalik Buterin says duh, go for the third option.

In fact, he says there is no such thing as the third option, yyyy-mm-dd is the only way to go about it.

My first job was with a firm called Genpact, and I was working for American clients, while being based out of Bangalore. mm-dd or dd-mm is a real problem, believe me.

Now, as an Indian, I’m tempted to say that dd-mm-yy is the “correct” way to go about it. Partially out of habit, as I’ve been writing dates in this format for all my life, but Vitalik Buterin does not approve:

But I’ve also argued in the past that writing the date in dd-mm-yyyy format makes sense because of an implicit order and logic in this way of writing it. The component that changes the most frequently (the day) comes first, the one that changes the second most frequently (the month) comes second, and the one that literally changes once a year comes third.

And if only the Americans hadn’t decided to go down the mm-dd-yyyy (why, America, why?), we could all have agreed upon this, and lived happily ever after.

But after much sighing and gnashing of teeth, I find myself – reluctantly – in Camp Buterin. yyyy-mm-dd is the only correct way to do it, as it removes any chance of ambiguity. dd-mm-yyyy is, I still hold, more logical, but yyyy-mm-dd has the least chance of confusion.

And this stuff matters, because dates can get really tricky when it comes to software. For exanple, did you know that dates in Excel are off by one day?