---
id: f41437f1-359e-41c9-894b-e5785c29d729
title: CommonJS
---

# Syntax

``` javascript
const ordinal = require("ordinal");
const {days, months} = require("date-names");

exports.formatDate = function(date, format) {
  return format.replace(/YYYY|M(MMM)?|Do?|dddd/g, tag => {
    if (tag == "YYYY") return date.getFullYear();
    if (tag == "M") return date.getMonth();
    if (tag == "MMMM") return months[date.getMonth()];
    if (tag == "D") return date.getDate();
    if (tag == "Do") return ordinal(date.getDate());
    if (tag == "dddd") return days[date.getDay()];
  });
};
```

``` javascript
const {formatDate} = require("./format-date");

console.log(formatDate(new Date(2017, 9, 13),
                       "dddd the Do"));
// → Friday the 13th
```