Parliament deleted eleven dates, not eleven days

In Britain and its dominions, September 2, 1752, was followed by September 14. The eleven dates between them did not occur.

The days did. People went to bed once and woke up once. Parliament had changed the labels to bring the British calendar into line with the Gregorian one used across much of Europe.

The distinction sounds obvious until money is attached. If a lease said rent was due on a certain date, should the calendar reform make the payment arrive eleven actual days sooner? Should a fair tied to the agricultural season move closer to summer? Should a lender collect interest for dates that had been removed from the calendar?

The Calendar (New Style) Act 1750 answered these questions by using two kinds of time. Courts, elections and corporate meetings generally remained on their old nominal dates. Their labels stayed put, so relative to the seasons they moved eleven days earlier.

Fairs and marts were treated differently. They remained on the same natural days and acquired later dates. The same protection applied to the opening and closing of common lands. Existing rents, annuities, leases and contracts were not to be accelerated. Interest was payable only for “the true number of natural days” that money remained outstanding.

This made the reform less like deleting time than converting a database while preserving selected meanings. For a court sitting, September 29 meant the square labelled September 29. For an old lease or seasonal fair, it meant the point in the year that used to have that label.

The statute changed one calendar, but it could not impose one answer to what a date was. Sometimes it was a name. Sometimes it was elapsed time. Sometimes it was when the livestock were expected to arrive.