Use of commas when writing date range in a sentence [closed]

Should there be a comma after 2014 in the following sentence?

From June 1, 2014 through April 30, 2015, there were 40 accidents on one stretch of road.

In your example there should be a comma after 2014.

No comma is needed in dates 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.

When specifying one or more days, however, there are two commonly accepted styles, month-day-year and day-month-year. Your example is of month-day-year, for which standard practice is to set the year off with commas. So:

From June 1, 2014, through April 30, 2015, there were 40 accidents on one stretch of road.
The year following March 1, 2020, seemed to stretch on without end.

For reference, below are some authoritative explanations.

From the MLA Style Center:

As the MLA Handbook (sec. 1.5) explains, when writing dates, you should "be consistent in your use of either the day-month-year style (12 January 2014) or the month-day-year style (January 12, 2014). In the latter style, the comma before the year has to be balanced by one after if there is no other punctuation after the year."

The exhibit ran from 2 June 1995 to 4 April 1996 in New York.
The exhibit ran from June 2, 1995, to April 4, 1996, in New York.

The Chicago Manual of Style (§6.38) agrees:

In the month-day-year style of dates, commas must be used to set off the year—a traditional usage that not only applies the logic of commas in pairs (see 6.17) but also serves to separate the numerals for day and year... Commas are...unnecessary where month and year only are given...
In the day-month-year system—useful in material that requires many full dates (and standard in British English)—no commas are needed to set off the year.

The performance took place on February 2, 2006, at the State Theatre in Ithaca.
Her license expires sometime in April 2021.
On Thanksgiving Day 1998 they celebrated their seventy-fifth anniversary.
The accused gradually came to accept the verdict. (See his journal entries of 6 October 2015 and 4 January 2017.)