In your example there should be a
after 2014. No
is needed in
that have a year and month (or a season), or a year only. For example: In July 1983 we went to the circus. For our autumn 2021 costume party the theme will be mask-friendly. By 2030 gila monsters will be perfectly ordinary companion animals.
Determining whether to include a comma after the year in your writing is subjective, as there is no definitive answer. If you are publishing your work, the decision to use a comma may depend on the preferences of the editor(s)/publisher.
One can refer to different style manuals, such as The Associated Press Stylebook, the Chicago Manual of Style, and the MLA Handbook, to find varying opinions.
In the case of certain examples (specifically, the first and fifth ones highlighted in yellow), the presence of commas appears to be incorrect to me. However, encountering stylistic dilemmas often indicates the need to rephrase the sentence. For example, it would be more appropriate to say “The article from November 15, 1908.” When using a noun phrase as a modifier in this manner, it should be relatively brief. Similarly, I find neither of these options satisfactory:
On November 28, 1935, it was a known fact that he was asleep.
On November 28, 1935, it was discovered that he was asleep.
The first one gives the impression that it was in the year 1935 when he was discovered sleeping. Moreover, in the second sentence, “found him sleeping” feels disconnected from the remainder of the phrase.