Petromax 821

Hi,

I got Petromax 821 last week.
But I don't know when it was made.

 

Hi Yosh,
if there are 4 digits stamped on the bottom, the production date can be read like follows:
"wwyd", where
ww stands for the calendar week: 1 ... 52
y stands for year of production: 1 = 1961 ... 9 = 1969
d stands for day of the week: 1 = Monday ... 7 = Sunday

As an example 1523 would mean:
15th week of 1962, day 3 (Wednesday), which should be the 11th of April, 1962

Hope that helps,
Martin K.

 

Hi Martin,

Thank you for letting me know how to decode 4 digits.

It was stamped "2914" on bottom of the tank.
So my 821 was made on Jul. 20.1961(Thursday).

Cheers,
Yosh

 

Here's my Petromax 826, Year 1961 running on diesel fuel instead of kerosene. No problems lighting it up(after preheating with 3 successive cups of meths/alcohol). No soot, no odor, clean burning.

 

Nice lantern the Petromax 821.
And the 827 too.
Both 250cp lanterns.
Best , and most beautiful ever.
Regards
Willi

 

Hello, I have a Petromax 821/250 cp that has the following numbers on the bottom of the tank: 3555. I tried to decipher as indicated by Martin K. (wwyd) and if I still know how to do the math my Petromax was manufactured in the 35th week of the year 1965 on day 5. Roughly speaking the date is September 5, 1965 SUNDAY. German workers in 1965 also worked on Sundays or, I think, I miscalculated. Mystery. See you next time

 

The 5th day is always Friday.It wasn't a holiday either.

 

Why would the 5th day be a sunday?

 

(big smile of embarrassment). I miscalculated by mistaking the day of the week . lamp built therefore on September 3, 1965.

I wish you a happy holiday wherever you are.

 

I have always doubted my own understanding of those dating digits .
Let's take the 1960s system as example.
Accordingly, the first two digits would indicate the week of the year.
The third digit: nth year within the 1960s decade.
The fourth digit: day of the week.
What I'm not quite sure is the fourth digit.
Example, if the fourth digit is 5, would that mean the 5th day of any week in general, or the 5th day of the specific week stated by the first two digits of that particular year stated by the third digit?
To confuse further, the first day of any week starts with a Sunday as shown in this 1965 calender: -

 

The first day is always defined as Monday of the calendar week. So there should not be any confusion.
However, it's not that simple to determine the decade. This thread should give you more information than you want...

 

That was a long and interesting thread @Martin K.

Then it is certainly much easier to remember

 

I have a new Petro 821/250 with the code under the tank 0301. So it was produced Monday, January 18, 1960.
Please tell me if I'm wrong this time too.
Thank you, it is a pleasure to talk with you.
Please bear with me.