Deciphering date code of my 100-400 L lens?

[mark_stephan2]

<p>How do I decipher this date code? The code is UB0323. I bought the lens a couple of months ago from my local camera store. </p>

[hop_phan]

<p>Hi Mark,<br>

Look at this link: http://www.kenrockwell.com/canon/date-codes.htm</p>

[mark_stephan2]

<p>If I'm reading this correctly then my brand new lens purchased in September 2015 was made in 1987 because the B in UB means 1987? I find it hard to beleive since the lens starting hitting the shelves in November 1998. If I use the the letter U in the date code which is the first letter you come up with 2006 which imo is more accurate. The date code on my 28-80/2.8-4.0L is UE1209 with E indicating it was made in 1990 which sounds correct since the lens was introduced in 1989. So it looks like Canon used both the first letter for some lenses and the second letter for newer lenses.<br>

28-80 uses the letter E in the code UE1209 to indicate it was manufactured in 12/90.<br>

100-400 uses the letter U in the code to indicate it was manufactured in 3/2006.</p>

[peter_rowe]

<p>The "U" means the manufacturing site is "Utsunomiya", the "B" means the year is "2013". The "0323" is an internal Canon manufacturing code.<br>

<a href="http://eflens.com/lens_articles/canon_lens_date_codes.html">http://eflens.com/lens_articles/canon_lens_date_codes.html</a></p>