Pi Day - Celebrate pi day by eating pies

Pi day has rolled around once more: the day when mathematics fans everywhere – particularly in the US, where the date is written 3.14 – celebrate everyone's favourite mathematical constant.

If you are wondering about the best time of day to celebrate, unfortunately you have already missed it. The first few digits, 3.14159, translates this year into March 14 at 1:59 am. It will be at a more sociable hour in four years' time, when the festivities should kick off on 3.14.15 at 9:26:53.

Don't let the niceties of timing put you off, though. Princeton University has already celebrated with an extended weekend of events, culminating in a celebration of Pi day itself. The four-day event included pi recitations, pie eating contests, and pi shopping deals for $3.14 or $31.40. Today is also Albert Einstein's birthday, leading to the inevitable creation of the Einstein Pie.

But don't worry if you can't make it to a pi party in person. You can still dial in. Pi fan Christopher Poole has set up a pi phone – call the US telephone number 253 243-2504 to hear the digits read out. Don't listen for too long, though: since pi goes on forever, who knows how much it could add to your phone bill.