Year on Boarding Pass?
 

Why isn't the year printed on boarding passes along with the month and day?

I found a couple of my old BPs in a book yesterday but I can't tell when they are from. The origin and destination are places I fly at least a couple of times a year, but the connecting city is one that is no longer available for that pair.

No big deal - I just wish I could tell what year they are from!

(I searched for a likely FT thread that would answer this question and couldn't find one. I also tried a web search and came up empty.)

Perhaps when airline systems were written eons ago, memory was so valuable that they decided there was next to zero chance that the same flight/gate/date/time would exist in future years, so they saved space. Y2K-style.

Maybe as just another precaution so that if someone finds it, it would be even more work to try to get on the flight. Not sure, just a theory

Could be.

I do find it interesting that some recent boarding passes lack the year of the flight, but the printed bag tags for the same flight do include the year.

Different programming, maybe?

There has never been a need for it as tickets cannot be bought more than 365 days in advance.

That and it's a good bet that there's a code on it somewhere that indicates exact date.

Update
 

FWIW, I found a semi-recent DL BP (2014) that had the year on it. But other, more recent, ones didn't.

Go figure.

I have a KE boarding pass here (stub only, which to me indicates they live in the past) that states '02APR17'.

Depends on Airline/Carrier aswell.. all my EW/4U BP have a year on it - LH/LX does not (even not in the barcode).

The IATA standard for the flight date in the barcode is simply to include the day of the year (1-365), not the year number for the flight date. But it also includes the date the BP was issued that does include a year marker, though only the last digit of the year. So a BP issued in 2017 or 2027 would be the same in that regard.
Save memory and because airlines do not sell flights more than a year in advance so each date can only exist once in the system. Even if the flight number, departure time and city pair remains the same. And for many airlines it does. LH400 has been flying between JFK and FRA for a long time now.

OP has not specified a carrier, so without specifics, you get a general answer.

First, presuming that the carrier uses bar-codes or some other form of coding, anything written on a BP is simply window-dressing. The BP is certainly coded for a specific flight departing a specific airport on a specific date.

Second, few if any carriers issue BP's more than 48 hours in advance. Most no more than 24 hours. Thus, no matter when you purchase a ticket, the BP is good for a gflight in the next 1-2 days.

Last ---- General rule of thumb is to populate only those fields required for the piece of paper (and we're talking about one of those) in question.