Earth Day or Earth's Day: Which is Correct?

By Carly Forsaith, updated on November 28, 2023

Every year, we honor the planet we inhabit on the day known as Earth Day. Or is it Earth's Day? If you're wondering how to spell it, look no further. In this article, we'll learn the correct spelling for the annual holiday and why it's written that way.

If you just want the quick version, here it is:

  • Earth Day is not a possessive noun, so you don't need to use an apostrophe and 's.' Just spell it 'Earth Day.' 

What Is Earth Day?

The first Earth Day took place on April 22, 1970, and it is often credited with helping to spur the modern environmental movement. The idea for Earth Day was proposed by American Senator Gaylord Nelson, who was inspired by the anti-Vietnam War "teach-ins" that took place on college campuses. He wanted to channel that energy and enthusiasm toward environmental issues.

Since then, we've honored the planet we live on every year on that date, and it's grown into a global event, with millions of people participating in activities such as tree planting, beach cleanups, environmental education programs, and more. It's a reminder to care for the planet and show gratitude for the resources it provides.

Why Isn't it Spelled Earth Day?

Some people spell this annual commemoration with an apostrophe followed by the letter 's,' making it 'Earth's Day.' But this is incorrect, and I'll tell you why.

First of all, it's important to note that an apostrophe can do two things:

  • Stand for omitted letters.
    We are → We're
  • To form a possessive noun.
    The photographer's wife.

Many holidays indeed take on the possessive form.

Here are just a few:

  • Mother's Day
  • Valentine's Day
  • April Fools' Day

But then again, many don't, like:

  • Veterans Day
  • Fourth of July
  • Christmas Day

Earth Day falls into that last category: it isn't a possessive noun and is always spelled Earth Day.

Some say this is because using the possessive form 'Earth's Day' could be interpreted as a day for Earth to celebrate itself. The organizers likely wanted to convey the idea that the day is about humans recognizing their role as stewards of the Earth and taking action to protect and preserve the environment.

In language, subtle choices like this can influence how people perceive and interpret the purpose of an event.

  • 'Earth Day' captures the essence of a day dedicated to the Earth and underscores the shared responsibility of humanity in caring for our planet.

But the simple truth is that we can theorize all we want, but the final decision on the official spelling of a holiday/celebration is down to the creator. And Mr. Nelson wanted it to be 'Earth Day,' so 'Earth Day' is what it is.

Should You Capitalize Earth Day?

Okay, so we've covered the correct spelling of this phrase and the reasons why. You might have noticed throughout this article that I have been capitalizing the words 'Earth' and 'Day.'

  • Regarding capitalization, the rule is pretty straightforward: always capitalize proper nouns.

Official names of holidays and celebrations are considered proper nouns, and Earth Day is the official name of a celebration, so the words should be capitalized when you use them together.

If you use the words separately, that's a different story. The term 'earth' on its own isn't a proper noun, and neither is 'day.' Here is an example of these words used as common nouns:

The earth rotates on its axis, causing day and night.

Example Sentences

Now that we've covered the proper use of apostrophes and when to capitalize the words, let's look at some examples of the term All Saints' Day in sentences. Here they are:

Every year on April 22nd, whether it rains or shines, people around the world celebrate Earth Day to raise awareness about environmental issues.

I can't come camping this weekend; you know every year on Earth Day I volunteer to plant trees.

Many schools incorporate Earth Day activities into their curriculum to teach students about the importance of environmental conservation.

Organizations and communities come together on Earth Day to launch initiatives that reduce their ecological footprint.

Earth Day serves as a reminder that each individual plays a role in protecting the planet and promoting a more sustainable future. 

Concluding Thoughts

That brings us to the end of this article about this popular celebration. Let's summarize what we've learned:

  • Earth Day isn't a possessive noun, so it should be written without the apostrophe and 's.'
  • Apostrophes make a noun possessive. Earth's Day is never correct.
  • It's the name of a holiday, so both words should be capitalized when used together.

If you'd like to learn about more national holidays and other confusing words, check out our dedicated blog. There, you'll find many other articles like this one, where you can learn how to spell holiday names correctly.

We encourage you to share this article on Twitter and Facebook. Just click those two links - you'll see why.

It's important to share the news to spread the truth. Most people won't.

Written By:
Carly Forsaith
Carly Forsaith is one of the lead freelance writers for Carly is a copywriter who has been writing about the English language for over 3 years. Before that, she was a teacher in Thailand, helping people learn English as a second language. She is a total grammar nerd and spends her time spotting language errors on signs and on the internet.

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