Today is Ash Wednesday. For many in the Christian faith it marks the beginning of the Easter period in the liturgical calendar. Growing up in Ireland, it was drilled into me in primary school that Lent had 40 days. This is a good example of a business rule that has become ingrained in an organisation to the point of being “conventional wisdom”. Such rules are not always correct (JK Galbraith did not intend “conventional wisdom” as a compliment), and when they are in error they can be difficult to shake. Even today if you were to ask an Irish person how long Lent is I would be fairly certain they’d answer 40 days.

The business rule that says that “Length(Lent)=40 days” is the kissing cousin of business rules like “Consumer customers only have one billing account“. There may be a kernel of truth to the rule, but it needs to be tested against available data or appropriate reference standards. By doing so you can test the accuracy of the rule, the appropriateness of the rule, and identify local variants to the rule that might need to be dealt with. As W. Edwards Deming said: “In God we trust. Everyone else must bring data”.

So how long is Lent?

The Business Rules and Standards:

  • Roman Catholics: Lent is the period from Ash Wednesday to the last Thursday before Easter Sunday. This is a period of 44 days. But as Sundays are not counted as days of observance for Lent in the Roman Catholic church this is actually a period of 38 days for Lent, over an elapsed period of 44 calendar days.
    • Exception 1: Irish Catholics get St. Patrick’s Day (17th March) off from Lent as well if it falls during the 44 calendar days, except if it falls on a Sunday. Think of it as a bit like a Leap Year. So Ireland: 44 calendar days, 37 days of observance, except if St Patrick’s Day is on a Sunday.
    • Exception 2: People living in most of the Archdiocese of Milan, which follows the Ambrosian Rite. The Ambrosian Rite starts Lent on the Sunday six weeks from Easter Sunday. Six weeks, Sundays excluded, means Lent is approximately 36 days.
  • Eastern Orthodox and Eastern Catholics follow the Rite of Constantinople start Lent on “Clean Monday”, 7 weeks before Pascha (Easter). The Easter Christian “Great Lent” lasts for 40 days, ending on the Friday of the 6th week. It is followed by Holy Week as a separate period up to Easter Sunday. Unlike Western Christianity, Sundays are included in the counting.
  • Anglican, Methodist, and other Western Christian traditions generally observe a Lent calendar that starts on Ash Wednesday and ends on Easter Saturday, with Sunday’s excluded from the counting. This corresponds to a period of 40 days of Lenten observance over a period of approximately 47 days, as Sundays are not included in the count.

So, based on those business rules, how long is Lent?

The most accurate answer I can give is “It depends. Between 6 and 7 weeks“. There is no generally applicable 40 day rule though.

Tying it back to Information Quality and Governance

Variations in business rules like this can occur quite frequently in business and can be very expensive to address during projects if they are not looked for and challenged early on to try and reduce variation. The classic example in Ireland in recent years was the PPARS HR system for the Health Service Executive which ran over budget by over €120 million, largely due to having to cater for extensive and unplanned variation in business rules around rosters and entitlements.

What would the implications be for your organisation if you found that consumer customers had more than one billing account? Are you in a business where customers may have multiple instances of service that you need to aggregate together in some way?

In God we trust. Everyone else must bring data!