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A little reason to celebrate

ZIP Code Day

History · July 1

ZIP codes are the five-digit numbers that help US mail find its way. Here is what they are, how they work and a few easy ways to notice them.

ZIP Code Day falls on Thursday, July 1, 2027. That is 247 days away.

Every address in the United States ends with a short string of digits that most people write without thinking. The ZIP code is a five-digit number used by the US Postal Service to sort and route mail to the right area.

The digits are not random. The first number points to a broad group of states, and the numbers that follow narrow things down toward a regional sorting center and then a local delivery area. Read left to right, a ZIP code works a bit like zooming in on a map.

There is also a longer version, often called ZIP+4, which adds four more digits after a hyphen. Those extra numbers point to a smaller slice of a delivery route, such as one side of a street or a single large building. Most people never use them, and the mail still arrives.

ZIP codes have drifted well beyond envelopes. Stores ask for them at checkout, websites use them to guess the weather, and people sometimes speak of a neighborhood by its number as if it were a name. For a string of digits, it carries a surprising amount of local identity.

Marking the occasion can be quiet. Look up the ZIP code of a place you have lived, or one from an old letter in a drawer, and see where the numbers sit on the map. Then look at the corner of the next envelope that arrives, where your own five digits are doing their job.

Ways to celebrate

• Look up the ZIP codes of every place you have lived.
• Write a letter and address it carefully, ZIP code included.
• Find which states share the same first ZIP code digit as yours.
• Try learning the ZIP+4 for your own address.

Dates

All national days on July 1

Also on July 1

• National Gingersnap Day
• National Creative Ice Cream Flavors Day
• International Joke Day
• National Postal Workers Day

Categories: History days