Currency is all about context, and it’s important to think about whether the publication date makes sense in relation to your argument. You might be looking for articles published last week for one paper, and resources from 60 years ago for another — it all depends on the topic and what your argument is.
If you’re writing about a science-related topic, it’s likely that you’re going to want to use current sources. Citing a research paper from the 1980s on HIV/AIDS will not have information as current or up-to-date as a medical journal published within the past couple of years. However, if you’re comparing initial treatments of HIV/AIDS and how they have progressed over time, using a source from 1987 could be beneficial.
Evaluating currency isn’t just useful for math and science. Historical analysis papers, for instance, may include primary sources, or articles from a certain time period. If you’re writing about World War II, citing a newspaper article from the 1942 could be extremely useful. Don’t forget, historians publish new viewpoints and reasoning behind historical events all the time, so just because a book was published last year, doesn’t mean it’s irrelevant to your history paper, either.