There are at least a couple of reasons why "the year is coming to an end" is the idiomatic choice. Firstly, "an end" better describes to the process or generality of something concluding, rather than pointing to a specific, singular conclusion. I will be coming tomorrow.

Understanding the Context

The act of "coming" here is taking a long time from the speaker/writer's point of view. One example where this would apply is if by "coming" the speaker/writer means the entire process of planning, packing, lining up travel, and actually traveling for a vacation. I will come tomorrow. future time - "Will come" or "Will be coming" - English Language ...

Key Insights

Is there a difference in meaning and usage between the two sentences below? (Both are happening in future) A) I'm not coming in for work today. B) I will not be coming in for work today. future tense - "I will not be coming" Vs. "I am not coming" - English ...

Final Thoughts