The proper way to format dates in America is to write month, day, comma, year. Like this:
May 27, 1950
However, as you are no doubt aware, this is the proper way to format a date in America. Different countries have different formats. And this is where we need to devote a tangent to Mr. Jonathan Swift, one of history’s most beloved satirists, the reason for which will be clear soon. (Feel free to skip this part if you want to get straight to the date discussion.)
A Swift Aside
The date format we use in America is called middle endian, but there is also the big endian and little endian formats. These terms derive from Jonathan Swift’s famous book, Gulliver’s Travels. One of the stories involves a political faction called Big Endians, people who liked to crack their eggs at the large end. The Lilliputian king considered this method too primitive and required his subjects, the Little Endians, to break their eggs at the small end. But the Big Endians rebelled.
Here is a quote from the book about these two groups:
“It is allowed on all Hands, that the primitive way of breaking Eggs, before we eat them, was upon the larger End: But his present Majesty’s Grandfather, while he was a Boy, going to eat an Egg, and breaking it according to the ancient Practice, happened to cut one of his Fingers. Whereupon the Emperor his Father published an Edict, commanding all his Subjects, upon great Penalties, to break the smaller End of their Eggs. The People so highly resented this Law, that our Histories tell us there have been six Rebellions raised on that account; wherein one Emperor lost his Life, and another his Crown. . . . It is computed, that eleven thousand Persons have, at several times, suffered Death, rather than submit to break their Eggs at the smaller End. Many hundred large Volumes have been published upon this Controversy: But the books of the Big Endians have been long forbidden. . . .”
And, somehow, someway, this is how we got the names for date formats; the system, itself, being called Endianness. Endianness is a system by which units are ordered based on size. In terms of calendar dates, the units are day, month, and year, with day being the smallest unit and year being the largest unit.
Little endian format
Most countries, including the vast majority of Europe, format their dates using the little endian method. This is why if you were to, say, pick up a British newspaper, you would see the date written with the day first, then the month, and then the year. As for commas, this format omits them.
Example: Hazel was born 27 May 1950.
However, I did find references that said a comma should be placed between the month and year if you are using an ordinal number (first, second, 1st, 2nd). In this case, an example would be:
Hazel was born 27th May, 1950.
Middle endian format
As we discussed earlier, America uses the middle endian format, joined by only a few other countries. In this format, the month goes first, then the day, then a comma, and then the year. Since the month is the middle-sized unit in the date, this format is called middle endian.
Example: Hazel was born May 27, 1950.
Big endian format
The international formal standard for formatting dates follows the big endian format, with the year coming first, then the month (since it is one step smaller than the year), and then the date.
Example: Hazel was born 1950 May 27th.
In the big endian format, there are no commas.
What about commas after the year?
Recently I had a comma debate with a work colleague. (If you’re not a copy editor, grammarian, or punctuation purist, this is exactly the type of conversation during which it would be easy to fall asleep. But to us, it was heated; it was enthralling; and it had just a hint of danger.) The question involved whether with a date in a sentence to include a comma after the year (when using the middle endian format).
To me, the answer was obvious: Yes, of course you put a comma there. And I prepared my list of references to back me up. To her, the answer was unclear. She also had a list of references that said it can go either way. (Grammar Girl, for one, is unfortunately on her side.) Well, I consider her references to be rogues, Grammar Girl or not.
So, it depends on what references you choose to follow. In the majority of my work, I adhere to The Chicago Manual of Style and the Associated Press Stylebook, and they say a sentence with a full date should look like this:
Hazel’s birthday of May 27, 1950, was a beautiful day.