[cratermoon]

So what's the guideline for tagging a submission with the date?

[coldtea]

It makes sense to add it if the content of the submission is time-sensitive and so knowledge of the date makes a difference (e.g. an article about some "new breakthrough discovery" which woudn't be such anymore if the piece was written in 2004).

[AnimalMuppet]

In general, the HN style is that, if it wasn't written this year, tag it with the year.