I took Japanese levels 1-4 in high school. Throughout those years I learned many things, usually lots of grammar and sentence structures in the form of learning about certain topics like food, travel, school, shopping, etc. Japanese 4 was the most difficult, not because of the high level, but because of the different learning structures.

Here is a time vocabulary worksheet from 2019, Japanese 1, my 9th-grade year.

This worksheet taught me more vocabulary concerning telling time, this worksheet was not difficult at all even in Japanese 1.