Using 年代 for decades when using 昭和XX年 for individual years

Question

If you are describing a year as

昭和４１年

rather than

１９６６年

Can you similarly use 年代 for decades, such as

昭和４０年代

or does that convention only apply when using the Christian calendar

Answer 1

Yes, you can safely use 年代 like that. 昭和40年代 refers to 1965–1974.

Note that 年代 does not always refer to decades. For example, 1600年代 typically refers to 1600–1699.