diff --git a/timezone-js/timezone-js.d.ts b/timezone-js/timezone-js.d.ts
index 50b9c3f369..ecf7d9e489 100644
--- a/timezone-js/timezone-js.d.ts
+++ b/timezone-js/timezone-js.d.ts
@@ -8,23 +8,73 @@
 declare module "timezone-js" {
 	export var timezone: TimezoneJs;
 
-	export var Date: {
-		new (timezone?: string): TimezoneJsDate;
-		new (time: string, timezone?: string): TimezoneJsDate;
-		new (year?: number, month?: number, day?: number, hour?: number, minute?: number, second?: string, timezone?: string): TimezoneJsDate;
-	};
-
-	export interface TimezoneJsDate extends Date {
+	export class Date {
+		constructor(timezone?: string);
+		// Note due to naming conflict I have not found a way to introduce the constructor
+		// that takes a regular Date object. Instead, I defined it to take an Object.
+		constructor(date: Object, timezone?: string);
+		constructor(utcMillis: number, timezone?: string);
+		constructor(time: string, timezone?: string);
+		constructor(year?: number, month?: number, day?: number, hour?: number, minute?: number, second?: number, millisecond?: number, timezone?: string);
 		setTimezone: (timezone: string) => void;
+
+		// regular Date members
+		toString(): string;
+		toDateString(): string;
+		toTimeString(): string;
+		toLocaleString(): string;
+		toLocaleDateString(): string;
+		toLocaleTimeString(): string;
+		valueOf(): number;
+		getTime(): number;
+		getFullYear(): number;
+		getUTCFullYear(): number;
+		getMonth(): number;
+		getUTCMonth(): number;
+		getDate(): number;
+		getUTCDate(): number;
+		getDay(): number;
+		getUTCDay(): number;
+		getHours(): number;
+		getUTCHours(): number;
+		getMinutes(): number;
+		getUTCMinutes(): number;
+		getSeconds(): number;
+		getUTCSeconds(): number;
+		getMilliseconds(): number;
+		getUTCMilliseconds(): number;
+		getTimezoneOffset(): number;
+		setTime(time: number): number;
+
+		// Note the setters have a non-void return type. Date has them as well, according to TypeScript 
+		setMilliseconds(ms: number): number;
+		setUTCMilliseconds(ms: number): number;
+		setSeconds(sec: number, ms?: number): number;
+		setUTCSeconds(sec: number, ms?: number): number;
+		setMinutes(min: number, sec?: number, ms?: number): number;
+		setUTCMinutes(min: number, sec?: number, ms?: number): number;
+		setHours(hours: number, min?: number, sec?: number, ms?: number): number;
+		setUTCHours(hours: number, min?: number, sec?: number, ms?: number): number;
+		setDate(date: number): number;
+		setUTCDate(date: number): number;
+		setMonth(month: number, date?: number): number;
+		setUTCMonth(month: number, date?: number): number;
+		setFullYear(year: number, month?: number, date?: number): number;
+		setUTCFullYear(year: number, month?: number, date?: number): number;
+		toUTCString(): string;
+		toISOString(): string;
+		toJSON(key?: any): string;
 	}
 
+
 	export interface TimezoneJs {
 		zoneFileBasePath: string;
-		loadingScheme: TimezoneJsLoadingScheme;
+		loadingScheme: number;
 		loadingSchemes: TimezoneJsLoadingSchemes;
 
 		transport(opts: TimezoneJsOptions): any;
 		init(opts?: TimezoneJsOptions): any;
+		getAllZones(): string[];
 	}
 
 	export interface TimezoneJsOptions {
@@ -34,12 +84,9 @@ declare module "timezone-js" {
 		url?: string;
 	}
 
-	export interface TimezoneJsLoadingScheme {
-	}
-
-	export enum TimezoneJsLoadingSchemes {
-		PRELOAD_ALL,
-		LAZY_LOAD,
-		MANUAL_LOAD
+	export class TimezoneJsLoadingSchemes {
+		PRELOAD_ALL: number;
+		LAZY_LOAD: number;
+		MANUAL_LOAD: number;
 	}
  }