diff --git a/README.md b/README.md
index aae2b13..f04430f 100644
--- a/README.md
+++ b/README.md
@@ -292,7 +292,7 @@ jsesc(['a', 'b', 'c'], {
 
 #### `json`
 
-The `json` option takes a boolean value (`true` or `false`), and defaults to `false` (disabled). When enabled, the output is valid JSON. [Hexadecimal character escape sequences](https://mathiasbynens.be/notes/javascript-escapes#hexadecimal) and [the `\v` or `\0` escape sequences](https://mathiasbynens.be/notes/javascript-escapes#single) are not used. Setting `json: true` implies `quotes: 'double', wrap: true, es6: false`, although these values can still be overridden if needed — but in such cases, the output won’t be valid JSON anymore.
+The `json` option takes a boolean value (`true` or `false`), and defaults to `false` (disabled). When enabled, the output is valid JSON. [Hexadecimal character escape sequences](https://mathiasbynens.be/notes/javascript-escapes#hexadecimal) and [the `\v` or `\0` escape sequences](https://mathiasbynens.be/notes/javascript-escapes#single) are not used. Setting `json: true` implies `quotes: 'double', wrap: true, es6: false`, although these values can still be overridden if needed — but in such cases, the output won’t be valid JSON anymore. In general, the `json` flag attempts to mimick the coercion behavior of `JSON.stringify` - `Date` objects will be formatted as strings, `Set` objects will become empty objects `{}`, and `undefined` values in an array will become `null`.
 
 ```js
 jsesc('foo\x00bar\xFF\uFFFDbaz', {
@@ -321,6 +321,9 @@ jsesc([ undefined, -Infinity ], {
   'json': true
 });
 // → '[null,null]'
+
+jsesc({ '!date': new Date(), '!set': new Set([1, 2])) });
+// → {"!date":"2020-04-03T15:34:00.000Z","!set":{}}
 ```
 
 **Note:** Using this option on objects or arrays that contain non-string values relies on `JSON.stringify()`. For legacy environments like IE ≤ 7, use [a `JSON` polyfill](http://bestiejs.github.io/json3/).
diff --git a/jsesc.js b/jsesc.js
index 7b8b923..866104f 100644
--- a/jsesc.js
+++ b/jsesc.js
@@ -35,6 +35,9 @@ const isObject = (value) => {
 	// This is a very simple check, but it’s good enough for what we need.
 	return toString.call(value) == '[object Object]';
 };
+const isDate = (value) => {
+	return toString.call(value) == '[object Date]';
+};
 const isString = (value) => {
 	return typeof value == 'string' ||
 		toString.call(value) == '[object String]';
@@ -134,7 +137,7 @@ const jsesc = (argument, options) => {
 	}
 
 	if (!isString(argument)) {
-		if (isMap(argument)) {
+		if (!json && isMap(argument)) {
 			if (argument.size == 0) {
 				return 'new Map()';
 			}
@@ -144,7 +147,7 @@ const jsesc = (argument, options) => {
 			}
 			return 'new Map(' + jsesc(Array.from(argument), options) + ')';
 		}
-		if (isSet(argument)) {
+		if (!json && isSet(argument)) {
 			if (argument.size == 0) {
 				return 'new Set()';
 			}
@@ -205,6 +208,9 @@ const jsesc = (argument, options) => {
 			if (useOctNumbers) {
 				return '0o' + argument.toString(8);
 			}
+		} else if (isDate(argument)) {
+			// Date objects have a toJSON method, which implies json: false here.
+			return 'new Date(' + jsesc(argument.valueOf(), options) + ')';
 		} else if (!isObject(argument)) {
 			if (json) {
 				// For some values (e.g. `undefined`, `function` objects),
diff --git a/src/jsesc.js b/src/jsesc.js
index d3eaff1..47fb7e4 100644
--- a/src/jsesc.js
+++ b/src/jsesc.js
@@ -35,6 +35,9 @@ const isObject = (value) => {
 	// This is a very simple check, but it’s good enough for what we need.
 	return toString.call(value) == '[object Object]';
 };
+const isDate = (value) => {
+	return toString.call(value) == '[object Date]';
+};
 const isString = (value) => {
 	return typeof value == 'string' ||
 		toString.call(value) == '[object String]';
@@ -134,7 +137,7 @@ const jsesc = (argument, options) => {
 	}
 
 	if (!isString(argument)) {
-		if (isMap(argument)) {
+		if (!json && isMap(argument)) {
 			if (argument.size == 0) {
 				return 'new Map()';
 			}
@@ -144,7 +147,7 @@ const jsesc = (argument, options) => {
 			}
 			return 'new Map(' + jsesc(Array.from(argument), options) + ')';
 		}
-		if (isSet(argument)) {
+		if (!json && isSet(argument)) {
 			if (argument.size == 0) {
 				return 'new Set()';
 			}
@@ -205,6 +208,9 @@ const jsesc = (argument, options) => {
 			if (useOctNumbers) {
 				return '0o' + argument.toString(8);
 			}
+		} else if (isDate(argument)) {
+			// Date objects have a toJSON method, which implies json: false here.
+			return 'new Date(' + jsesc(argument.valueOf(), options) + ')';
 		} else if (!isObject(argument)) {
 			if (json) {
 				// For some values (e.g. `undefined`, `function` objects),
diff --git a/tests/tests.js b/tests/tests.js
index 403b9c0..3541915 100644
--- a/tests/tests.js
+++ b/tests/tests.js
@@ -342,6 +342,18 @@ describe('common usage', function() {
 			'new Map([\n\t[\'a\', 1],\n\t[\'b\', new Map([\n\t\t[\'x\', 2],\n\t\t[\'y\', 3]\n\t])]\n])',
 			'Stringifying a Map with `compact: false`'
 		);
+		assert.equal(
+			jsesc(
+				new Map([
+					['a', 1]
+				]),
+				{
+					'json': true
+				}
+			),
+			'{}',
+			'Stringifying a Map with `json: true`'
+		);
 		assert.equal(
 			jsesc(
 				new Set([])
@@ -377,6 +389,19 @@ describe('common usage', function() {
 			'new Set([\n\t[\n\t\t\'a\'\n\t],\n\t\'b\',\n\t{}\n])',
 			'Stringifying a Set with `compact: false`'
 		);
+		assert.equal(
+			jsesc(
+				new Set([
+					['a'],
+					'b'
+				]),
+				{
+					'json': true
+				}
+			),
+			'{}',
+			'Stringifying a Set with `json: true`'
+		);
 		// Buffer
 		assert.equal(
 			jsesc(
@@ -395,6 +420,31 @@ describe('common usage', function() {
 			'Buffer.from([\n\t19,\n\t55,\n\t66\n])',
 			'Stringifying a Buffer with `compact: false`'
 		);
+		// Date
+		assert.equal(
+			jsesc(
+				new Date('2020-04-03T15:34:00Z')
+			),
+			'new Date(1585928040000)'
+		);
+		assert.equal(
+			jsesc(
+				new Date('2020-04-03T15:34:00Z'),
+				{
+					'numbers': 'hexadecimal'
+				}
+			),
+			'new Date(0x17140AD6E40)'
+		);
+		assert.equal(
+			jsesc(
+				new Date('2020-04-03T15:34:00Z'),
+				{
+					'json': true
+				}
+			),
+			'"2020-04-03T15:34:00.000Z"'
+		);
 		// JSON
 		assert.equal(
 			jsesc('foo\x00bar\xFF\uFFFDbaz', {