I am a Dutch author and I am writing a book about Ancient Egypt with lots of dates. My question is: can I use for instance 4,510 B.C.E. instead of 4510 B.C.E. Is there a rule for using the comma in dates?

3 Answers 3


Generally, we don't include commas in years. The current year is 2015, not 2,015.

However, if the year contains five or more digits, then you generally do add a comma. So there is no comma in 4510 B.C.E., but if you went even further into the past, you would add a comma to 14,510 B.C.E.

I found a few style guides to back this up, such as this one from National Geographic, and this one from ESC. Style guides offer suggestions, rather than hard-and-fast rules, and different organizations may have different suggestions. However, I think this suggestion is pretty consistent. We definitely write modern years, such as 1996, without commas, so it makes sense to write older years in the same way. Adding commas to larger numbers makes them easier to read, so you should do this with years, as well (10000000 B.C.E. is hard to understand at a glance, you have to pause in your reading for a second to count the zeroes; 10,000,000 B.C.E. is much easier to read).

  • You'll also see "10Mya", or "10 Ma ago", but generally in geology rather than Egyptology. Commented May 7, 2015 at 16:07

Don't use a comma.

The current year is 2015 and we pronounce that as "twenty fifteen", not "two thousand and fifteen" which is how it'd read if it were written as 2,015.

  • 3
    In the UK we'd refer to it as Two Thousand (and) Fifteen...`Twenty-Fifteen" is, in my experience, an Americanism. 2005 isn't referred to as Twenty-Five
    – Paulie_D
    Commented May 7, 2015 at 15:38
  • @Paulie_D Of course not! It would be Twenty-Aught-Five ;)
    – Sabre
    Commented May 7, 2015 at 15:58
  • @Sabre The "Naughty Aughties"...again, I think the "Aught" is an an americanism too.
    – Paulie_D
    Commented May 7, 2015 at 16:03
  • As usual in the UK, arguing about something is considered more interesting than doing it: telegraph.co.uk/culture/tvandradio/6897583/… Commented May 7, 2015 at 16:11
  • Dates through 1999 used "nineteen" because even the formal "nineteen hundred" is shorter than "one thousand nine hundred". For dates through 2009, "two thousand" was no longer than "twenty aught"; for dates through 2099, "two thousand" will be longer than "twenty", but inertia favors the former. Once 2100 rolls around, though, "twenty-one hundred" will be shorter than "two thousand one hundred".
    – supercat
    Commented May 7, 2015 at 16:40

The convention is to not put commas in years.

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