diff --git a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
index 8ff85cb15607..298c776bdf96 100644
--- a/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
+++ b/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/TypeScriptFetchClientCodegen.java
@@ -973,6 +973,14 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
             return TypeScriptFetchClientCodegen.getItemsDataType(this.items);
         }
 
+        public boolean isDateType() {
+            return isDate && "Date".equals(dataType);
+        }
+
+        public boolean isDateTimeType() {
+            return isDateTime && "Date".equals(dataType);
+        }
+
         public ExtendedCodegenParameter(CodegenParameter cp) {
             super();
 
@@ -1110,6 +1118,14 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
             return TypeScriptFetchClientCodegen.getItemsDataType(this.items);
         }
 
+        public boolean isDateType() {
+            return isDate && "Date".equals(dataType);
+        }
+
+        public boolean isDateTimeType() {
+            return isDateTime && "Date".equals(dataType);
+        }
+
         public ExtendedCodegenProperty(CodegenProperty cp) {
             super();
 
@@ -1361,6 +1377,14 @@ public class TypeScriptFetchClientCodegen extends AbstractTypeScriptClientCodege
         public String returnPassthrough;
         public boolean hasReturnPassthroughVoid;
 
+        public boolean isDateType() {
+            return isDate && "Date".equals(dataType);
+        }
+
+        public boolean isDateTimeType() {
+            return isDateTime && "Date".equals(dataType);
+        }
+
         public ExtendedCodegenModel(CodegenModel cm) {
             super();
 
diff --git a/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache b/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
index f494271ad648..24edd4d6ade8 100644
--- a/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-fetch/apis.mustache
@@ -123,17 +123,17 @@ export class {{classname}} extends runtime.BaseAPI {
         {{/isArray}}
         {{^isArray}}
         if (requestParameters.{{paramName}} !== undefined) {
-            {{#isDateTime}}
+            {{#isDateTimeType}}
             queryParameters['{{baseName}}'] = (requestParameters.{{paramName}} as any).toISOString();
-            {{/isDateTime}}
-            {{^isDateTime}}
-            {{#isDate}}
+            {{/isDateTimeType}}
+            {{^isDateTimeType}}
+            {{#isDateType}}
             queryParameters['{{baseName}}'] = (requestParameters.{{paramName}} as any).toISOString().substr(0,10);
-            {{/isDate}}
-            {{^isDate}}
+            {{/isDateType}}
+            {{^isDateType}}
             queryParameters['{{baseName}}'] = requestParameters.{{paramName}};
-            {{/isDate}}
-            {{/isDateTime}}
+            {{/isDateType}}
+            {{/isDateTimeType}}
         }
 
         {{/isArray}}
diff --git a/modules/openapi-generator/src/main/resources/typescript-fetch/modelGeneric.mustache b/modules/openapi-generator/src/main/resources/typescript-fetch/modelGeneric.mustache
index 9c6ebc44f31b..0d36547cfc2c 100644
--- a/modules/openapi-generator/src/main/resources/typescript-fetch/modelGeneric.mustache
+++ b/modules/openapi-generator/src/main/resources/typescript-fetch/modelGeneric.mustache
@@ -59,17 +59,17 @@ export function {{classname}}FromJSONTyped(json: any, ignoreDiscriminator: boole
         {{/additionalPropertiesType}}
         {{#vars}}
         {{#isPrimitiveType}}
-        {{#isDate}}
+        {{#isDateType}}
         '{{name}}': {{^required}}!exists(json, '{{baseName}}') ? undefined : {{/required}}({{#isNullable}}json['{{baseName}}'] === null ? null : {{/isNullable}}new Date(json['{{baseName}}'])),
-        {{/isDate}}
-        {{#isDateTime}}
+        {{/isDateType}}
+        {{#isDateTimeType}}
         '{{name}}': {{^required}}!exists(json, '{{baseName}}') ? undefined : {{/required}}({{#isNullable}}json['{{baseName}}'] === null ? null : {{/isNullable}}new Date(json['{{baseName}}'])),
-        {{/isDateTime}}
-        {{^isDate}}
-        {{^isDateTime}}
+        {{/isDateTimeType}}
+        {{^isDateType}}
+        {{^isDateTimeType}}
         '{{name}}': {{^required}}!exists(json, '{{baseName}}') ? undefined : {{/required}}json['{{baseName}}'],
-        {{/isDateTime}}
-        {{/isDate}}
+        {{/isDateTimeType}}
+        {{/isDateType}}
         {{/isPrimitiveType}}
         {{^isPrimitiveType}}
         {{#isArray}}
@@ -118,7 +118,7 @@ export function {{classname}}ToJSON(value?: {{classname}} | null): any {
         {{#vars}}
         {{^isReadOnly}}
         {{#isPrimitiveType}}
-        '{{baseName}}': {{#isDate}}{{^required}}value.{{name}} === undefined ? undefined : {{/required}}({{#isNullable}}value.{{name}} === null ? null : {{/isNullable}}value.{{name}}.toISOString().substr(0,10)){{/isDate}}{{#isDateTime}}{{^required}}value.{{name}} === undefined ? undefined : {{/required}}({{#isNullable}}value.{{name}} === null ? null : {{/isNullable}}value.{{name}}.toISOString()){{/isDateTime}}{{^isDate}}{{^isDateTime}}value.{{name}}{{/isDateTime}}{{/isDate}},
+        '{{baseName}}': {{#isDateType}}{{^required}}value.{{name}} === undefined ? undefined : {{/required}}({{#isNullable}}value.{{name}} === null ? null : {{/isNullable}}value.{{name}}.toISOString().substr(0,10)){{/isDateType}}{{#isDateTimeType}}{{^required}}value.{{name}} === undefined ? undefined : {{/required}}({{#isNullable}}value.{{name}} === null ? null : {{/isNullable}}value.{{name}}.toISOString()){{/isDateTimeType}}{{^isDateType}}{{^isDateTimeType}}value.{{name}}{{/isDateTimeType}}{{/isDateType}},
         {{/isPrimitiveType}}
         {{^isPrimitiveType}}
         {{#isArray}}
diff --git a/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchModelTest.java b/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchModelTest.java
index 9bc7c709487a..d1af770e2cd8 100644
--- a/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchModelTest.java
+++ b/modules/openapi-generator/src/test/java/org/openapitools/codegen/typescript/fetch/TypeScriptFetchModelTest.java
@@ -117,6 +117,76 @@ public class TypeScriptFetchModelTest {
         Assert.assertFalse(property5.isContainer);
     }
 
+    @Test(description = "convert a simple TypeScript Angular model; overwrite date/DateTime type mapping")
+    public void simpleModelWithStringDateTest() {
+        final Schema model = new Schema()
+                .description("a sample model")
+                .addProperties("id", new IntegerSchema().format(SchemaTypeUtil.INTEGER64_FORMAT))
+                .addProperties("name", new StringSchema())
+                .addProperties("createdAt", new DateTimeSchema())
+                .addProperties("birthDate", new DateSchema())
+                .addProperties("active", new BooleanSchema())
+                .addRequiredItem("id")
+                .addRequiredItem("name");
+
+        final DefaultCodegen codegen = new TypeScriptFetchClientCodegen();
+        OpenAPI openAPI = TestUtils.createOpenAPIWithOneSchema("sample", model);
+        codegen.setOpenAPI(openAPI);
+        codegen.typeMapping().put("date", "string");
+        codegen.typeMapping().put("DateTime", "string");
+        final CodegenModel cm = codegen.fromModel("sample", model);
+
+        Assert.assertEquals(cm.name, "sample");
+        Assert.assertEquals(cm.classname, "Sample");
+        Assert.assertEquals(cm.description, "a sample model");
+        Assert.assertEquals(cm.vars.size(), 5);
+
+        final CodegenProperty property1 = cm.vars.get(0);
+        Assert.assertEquals(property1.baseName, "id");
+        Assert.assertEquals(property1.dataType, "number");
+        Assert.assertEquals(property1.name, "id");
+        Assert.assertEquals(property1.defaultValue, "undefined");
+        Assert.assertEquals(property1.baseType, "number");
+        Assert.assertTrue(property1.required);
+        Assert.assertFalse(property1.isContainer);
+
+        final CodegenProperty property2 = cm.vars.get(1);
+        Assert.assertEquals(property2.baseName, "name");
+        Assert.assertEquals(property2.dataType, "string");
+        Assert.assertEquals(property2.name, "name");
+        Assert.assertEquals(property2.defaultValue, "undefined");
+        Assert.assertEquals(property2.baseType, "string");
+        Assert.assertTrue(property2.required);
+        Assert.assertFalse(property2.isContainer);
+
+        final CodegenProperty property3 = cm.vars.get(2);
+        Assert.assertEquals(property3.baseName, "createdAt");
+        Assert.assertEquals(property3.complexType, null);
+        Assert.assertEquals(property3.dataType, "string");
+        Assert.assertEquals(property3.name, "createdAt");
+        Assert.assertEquals(property3.defaultValue, "undefined");
+        Assert.assertFalse(property3.required);
+        Assert.assertFalse(property3.isContainer);
+
+        final CodegenProperty property4 = cm.vars.get(3);
+        Assert.assertEquals(property4.baseName, "birthDate");
+        Assert.assertEquals(property4.complexType, null);
+        Assert.assertEquals(property4.dataType, "string");
+        Assert.assertEquals(property4.name, "birthDate");
+        Assert.assertEquals(property4.defaultValue, "undefined");
+        Assert.assertFalse(property4.required);
+        Assert.assertFalse(property4.isContainer);
+
+        final CodegenProperty property5 = cm.vars.get(4);
+        Assert.assertEquals(property5.baseName, "active");
+        Assert.assertEquals(property5.complexType, null);
+        Assert.assertEquals(property5.dataType, "boolean");
+        Assert.assertEquals(property5.name, "active");
+        Assert.assertEquals(property5.defaultValue, "undefined");
+        Assert.assertFalse(property5.required);
+        Assert.assertFalse(property5.isContainer);
+    }
+
     @Test(description = "convert and check default values for a simple TypeScript Angular model")
     public void simpleModelDefaultValuesTest() throws ParseException {
         IntegerSchema integerSchema = new IntegerSchema().format(SchemaTypeUtil.INTEGER64_FORMAT);