Jack Taylor wrote:
"Martin Underwood" wrote in message
...

The code that they've used is quite cunning:
for vehicles registered between March and September, the two
digits are always the last two digits of the year; for vehicles
registered between September and March, the two digits are always
(year of the September) + 50.

What I still don't understand is what is going to happen in March
2011, if they continue with the present logic, which is to use '0'
to indicate March registrations and '5' to indicate September and
the other digit to represent the last digit of the year!

The logic is to use the last two digits of the year for Mar-Aug
registrations, ditto plus 50 for Sep-Dec, and the same code for Jan &
Feb of the following year. So Mar-Aug 2011 will be 11 and Sep 2011 to
Feb 2012 will be 61. This formula will be valid until 28 Feb 2051, the
last two 6-month periods using the codes 50 and 00.
--
Richard J.
(to e-mail me, swap uk and yon in address)