Was amused by the reaction of some friends about what days are in Lent. If you can work through the entry in the online Catholic Encyclopaedia, you'll see the exact timing and observance of Lent has changed over the centuries. However, the prevailing view in the Western Church seems to be that Lent runs from Ash Wednesday to Easter Eve (or some hold Maundy Thursday), omitting the Sundays. These are seen as days when the fasting of Lent could be relaxed a little (not a full reprieve, sorry!)
A further slight reprieve was traditionally allowed on the 4th Sunday of Lent or Laetere Sunday (Mothering Sunday to most people) when some concessions to celebration were traditionally allowed. A similar reprieve was traditional on the 3rd Sunday of Advent. You can even wear rose-coloured vestments, but I'll pass on that.
If you go by the Ash Wed - Easter Eve chronology and miss out the Sundays, that's 40 days. Easy innit?