Is 年 used commonly as a Japanese era marker?


I've just imported a car from Japan. There are a number of stickers on the car
that I don't need and so I am pulling them off one-by-one. Even though I may
not need to keep the stickers, there may be some information on them that may
be useful.

One of them says,

[code]

    自動車検査証の有効
    期間の満了する日
    5年1月21日
    
[/code]

Now I think this means, _evidence of validity period of vehicle inspection,
until year: Reiwa-5 (2023), month: January, day: 21_. But, Google Translate
doesn't translate the date that way. And neither can I find any reference to
referring to 令和 (Reiwa) with just "年". So, I thought I would check. **Is the
year specified, 2023?**

Footnote: Google Translate turns "5年1月21日" into "January 21, 5".




I think the answer is generally no.

The 5 in the sticker does mean 令和5年 as you understand, but usually if the year
indicates that of a Japanese era (昭和, 平成, 令和 etc), they are shown as such. The
stickers are exceptions.




The kanji 年 is a generic "unit" for year, just as 月 is for month and 日 is for
day of the month. 年 is used regardless of the era or the calendar type. The
calendar type or the era name can be specified before the number:

  * 紀元前3000年 = 3000 B.C.
  * 西暦2023年 = 2023 A.D.
  * 昭和48年 = Showa 48
  * 令和5年 = Reiwa 5
  * 宇宙世紀78年 = [Universal Century](https://gundam.fandom.com/wiki/Universal_Century) 0078

In your case, it is a convention to use the Japanese era system in these
vehicle inspection stickers, and the era name (令和) is not explicitly
specified. In other words, all you can do is remember that it's in Reiwa. This
system works because we understand these stickers are valid only for a few
years. In other business fields, such a convention is clearly confusing, so
people just use the Western calendar (2023年) or explicitly add the era name
(令和5年, or R5 for short).

