Thorn, Atlas, AEI Mazda Lamp Date Calculator
Thorn, Atlas, AEI lamps have a 2 digit date code, this calculator gives up to 4 (or 5) possible options of what that date might be, depending on which decade the lamp was made in- you'll have to decide which one applies most closely to the lamp in question. All this does, is remove the need for you to do the maths of which month code is which date.
This calculator will work for 3 (or 4- see below) of the 96 month cycles known to apply to this date code, starting at Jan 1966 for Thorn and Atlas, or late 50s for AEI Mazda, up to 1990. There were some Thorn lamps made in the early 1990s with this date code, the 4th result gives this option.
This was made possible following posts to Streetlighting UK by Mike Barford, Colin Grimes and Chris Millinship, May 2009.
This calculator will work for 3 (or 4- see below) of the 96 month cycles known to apply to this date code, starting at Jan 1966 for Thorn and Atlas, or late 50s for AEI Mazda, up to 1990. There were some Thorn lamps made in the early 1990s with this date code, the 4th result gives this option.
This was made possible following posts to Streetlighting UK by Mike Barford, Colin Grimes and Chris Millinship, May 2009.
James Hooker made the following comments about this sequence:
"Originally this was a GEC code, introduced with the opening of Hammersmith lampworks, January 1894 = code 01. Adopted by most other members of ELMA in May 1934, with code 05. Then also used by other Phoebus members, until the war when the Phoebus cartel collapsed. With the introduction of the 1948 Lamp Group, which superseded the Phoebus cartel, many companies then took the opportunity to introduced new codes, but GEC, BTH and Philips UK kept the old GEC system. GE used it right up to the closure of Leicester, but Enfield's similar code was offset by 3 years, similar to GE in USA."