It’s not often a leap year comes around. About once every four years, in fact.

To celebrate this year’s bonus day, which falls on Saturday, here are three puzzles about dates and births.

1. Philippe [geddit?] was born on 29 February 2016. His parents decided to celebrate his first birthday 365 days later.

On what date did they celebrate his first birthday?

2. My great grandmother was born on the first Sunday of the year. Her seventh birthday was also on a Sunday.

In which year was my great grandmother born?

3. The mother is 21 years older than her daughter. In six years she will be five times older than her daughter.

Where is the father?

I’ll be back with the solutions at 5pm UK time.

UPDATE: Click here for the solutions.

Meanwhile, NO SPOILERS please! Instead discuss what it is like to be born on February 29, or anything else about leap years.

I set a puzzle here every two weeks on a Monday. I’m always on the look-out for great puzzles. If you would like to suggest one, email me.

My latest book is So You Think You’ve Got Problems.