Hi Supersprout - It came free with a French garden magazine called Amis du Jardin and was probably the March issue. I wouldn't have bought it normally but I was looking for something to read over lunch whilst I was out hunting new tiles for the ground floor after a watery disaster.  I live in the French speaking area of Belgium and it was that or some gossipy stuff about minor European royals.
I just wish I could find it now for all the autumn lifting etc. I shall be looking actively for it next year as the calendar was great fun and the magazine not bad either. In case the French puts you off, each day has a symbol for fruit, veggies, flowers and roots so it's easy to work out. There are also two days in the lunar cycle when nothing should be done. These are the points where the moon is closest to and furthest from the earth in its orbiting and all garden activity - apart from sitting and enjoying or admiring it - are inauspicious. Our farmer neighbours across the road know about those without having a calendar!