How to Represent Dates in TypeScript

General Discussions
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1

Dates are not a specific TypeScript type, so how should you represent them? Should you use any or object? It seems like there should be a proper way to handle dates in TypeScript.

For instance:

let myDate: any = new Date();

I couldn’t find much information on Google about this simple question. What is the correct way to represent dates using the typescript date type?

2

The correct type for representing dates in TypeScript is Date:

const d: Date = new Date(); // The type can also be inferred automatically from 'new Date()'

Using the typescript date type ensures your code is type-safe and more readable.

3

TypeScript recognizes the Date interface natively, just like it does with number, string, or custom types. Therefore, you should use the typescript date type like this:

let myDate: Date = new Date();

This way, you benefit from TypeScript’s type-checking capabilities.

4

As mentioned, the type for dates in TypeScript is Date. This typescript date type is useful for enforcing at compile time that you are working with a Date object. Here’s an example of correct usage:


const date: Date = new Date();

function logDayNumber(date: Date) {

console.log(date.getDay());

}

// Works fine

logDayNumber(date);

// Compile-time error occurs if you forget the 'new' keyword

// Argument of type 'string' is not assignable to parameter of type 'Date'

logDayNumber(Date());

In the incorrect usage, Date() without new returns a string, which causes a compile-time error when passed to a function expecting a Date object. This is why using the typescript date type is crucial for maintaining type safety in your code.