类型为日期:

const d: Date = new Date(); // but the type can also be inferred from "new Date()" already

这和其他对象实例一样:)

每个类或接口都可以在TypeScript中用作类型。

 const date = new Date();

因为date是一个内部TypeScript对象，由DateConstructor接口引用。

对于你使用的构造函数，它被定义为:

interface DateConstructor {
    new(): Date;
    ...
}

为了让它更明确，你可以使用:

 const date: Date = new Date();

你可能会错过类型定义，日期是来自我的例子ES6库，在我的tsconfig。我已经定义了:

"compilerOptions": {
    "target": "ES6",
    "lib": [
        "es6",
        "dom"
    ],

您可以调整这些设置来针对您想要的JavaScript版本。

顺便说一下，Date是lib.es6.d.ts中的接口:

/** Enables basic storage and retrieval of dates and times. */
interface Date {
    /** Returns a string representation of a date. The format of the string depends on the locale. */
    toString(): string;
    /** Returns a date as a string value. */
    toDateString(): string;
    /** Returns a time as a string value. */
    toTimeString(): string;
    /** Returns a value as a string value appropriate to the host environment's current locale. */
    toLocaleString(): string;
    /** Returns a date as a string value appropriate to the host environment's current locale. */
    toLocaleDateString(): string;
    /** Returns a time as a string value appropriate to the host environment's current locale. */
    toLocaleTimeString(): string;
    /** Returns the stored time value in milliseconds since midnight, January 1, 1970 UTC. */
    valueOf(): number;
    /** Gets the time value in milliseconds. */
    getTime(): number;
    /** Gets the year, using local time. */
    getFullYear(): number;
    /** Gets the year using Universal Coordinated Time (UTC). */
    getUTCFullYear(): number;
    /** Gets the month, using local time. */
    getMonth(): number;
    /** Gets the month of a Date object using Universal Coordinated Time (UTC). */
    getUTCMonth(): number;
    /** Gets the day-of-the-month, using local time. */
    getDate(): number;
    /** Gets the day-of-the-month, using Universal Coordinated Time (UTC). */
    getUTCDate(): number;
    /** Gets the day of the week, using local time. */
    getDay(): number;
    /** Gets the day of the week using Universal Coordinated Time (UTC). */
    getUTCDay(): number;
    /** Gets the hours in a date, using local time. */
    getHours(): number;
    /** Gets the hours value in a Date object using Universal Coordinated Time (UTC). */
    getUTCHours(): number;
    /** Gets the minutes of a Date object, using local time. */
    getMinutes(): number;
    /** Gets the minutes of a Date object using Universal Coordinated Time (UTC). */
    getUTCMinutes(): number;
    /** Gets the seconds of a Date object, using local time. */
    getSeconds(): number;
    /** Gets the seconds of a Date object using Universal Coordinated Time (UTC). */
    getUTCSeconds(): number;
    /** Gets the milliseconds of a Date, using local time. */
    getMilliseconds(): number;
    /** Gets the milliseconds of a Date object using Universal Coordinated Time (UTC). */
    getUTCMilliseconds(): number;
    /** Gets the difference in minutes between the time on the local computer and Universal Coordinated Time (UTC). */
    getTimezoneOffset(): number;
    /**
      * Sets the date and time value in the Date object.
      * @param time A numeric value representing the number of elapsed milliseconds since midnight, January 1, 1970 GMT.
      */
    setTime(time: number): number;
    /**
      * Sets the milliseconds value in the Date object using local time.
      * @param ms A numeric value equal to the millisecond value.
      */
    setMilliseconds(ms: number): number;
    /**
      * Sets the milliseconds value in the Date object using Universal Coordinated Time (UTC).
      * @param ms A numeric value equal to the millisecond value.
      */
    setUTCMilliseconds(ms: number): number;

    /**
      * Sets the seconds value in the Date object using local time.
      * @param sec A numeric value equal to the seconds value.
      * @param ms A numeric value equal to the milliseconds value.
      */
    setSeconds(sec: number, ms?: number): number;
    /**
      * Sets the seconds value in the Date object using Universal Coordinated Time (UTC).
      * @param sec A numeric value equal to the seconds value.
      * @param ms A numeric value equal to the milliseconds value.
      */
    setUTCSeconds(sec: number, ms?: number): number;
    /**
      * Sets the minutes value in the Date object using local time.
      * @param min A numeric value equal to the minutes value.
      * @param sec A numeric value equal to the seconds value.
      * @param ms A numeric value equal to the milliseconds value.
      */
    setMinutes(min: number, sec?: number, ms?: number): number;
    /**
      * Sets the minutes value in the Date object using Universal Coordinated Time (UTC).
      * @param min A numeric value equal to the minutes value.
      * @param sec A numeric value equal to the seconds value.
      * @param ms A numeric value equal to the milliseconds value.
      */
    setUTCMinutes(min: number, sec?: number, ms?: number): number;
    /**
      * Sets the hour value in the Date object using local time.
      * @param hours A numeric value equal to the hours value.
      * @param min A numeric value equal to the minutes value.
      * @param sec A numeric value equal to the seconds value.
      * @param ms A numeric value equal to the milliseconds value.
      */
    setHours(hours: number, min?: number, sec?: number, ms?: number): number;
    /**
      * Sets the hours value in the Date object using Universal Coordinated Time (UTC).
      * @param hours A numeric value equal to the hours value.
      * @param min A numeric value equal to the minutes value.
      * @param sec A numeric value equal to the seconds value.
      * @param ms A numeric value equal to the milliseconds value.
      */
    setUTCHours(hours: number, min?: number, sec?: number, ms?: number): number;
    /**
      * Sets the numeric day-of-the-month value of the Date object using local time.
      * @param date A numeric value equal to the day of the month.
      */
    setDate(date: number): number;
    /**
      * Sets the numeric day of the month in the Date object using Universal Coordinated Time (UTC).
      * @param date A numeric value equal to the day of the month.
      */
    setUTCDate(date: number): number;
    /**
      * Sets the month value in the Date object using local time.
      * @param month A numeric value equal to the month. The value for January is 0, and other month values follow consecutively.
      * @param date A numeric value representing the day of the month. If this value is not supplied, the value from a call to the getDate method is used.
      */
    setMonth(month: number, date?: number): number;
    /**
      * Sets the month value in the Date object using Universal Coordinated Time (UTC).
      * @param month A numeric value equal to the month. The value for January is 0, and other month values follow consecutively.
      * @param date A numeric value representing the day of the month. If it is not supplied, the value from a call to the getUTCDate method is used.
      */
    setUTCMonth(month: number, date?: number): number;
    /**
      * Sets the year of the Date object using local time.
      * @param year A numeric value for the year.
      * @param month A zero-based numeric value for the month (0 for January, 11 for December). Must be specified if numDate is specified.
      * @param date A numeric value equal for the day of the month.
      */
    setFullYear(year: number, month?: number, date?: number): number;
    /**
      * Sets the year value in the Date object using Universal Coordinated Time (UTC).
      * @param year A numeric value equal to the year.
      * @param month A numeric value equal to the month. The value for January is 0, and other month values follow consecutively. Must be supplied if numDate is supplied.
      * @param date A numeric value equal to the day of the month.
      */
    setUTCFullYear(year: number, month?: number, date?: number): number;
    /** Returns a date converted to a string using Universal Coordinated Time (UTC). */
    toUTCString(): string;
    /** Returns a date as a string value in ISO format. */
    toISOString(): string;
    /** Used by the JSON.stringify method to enable the transformation of an object's data for JavaScript Object Notation (JSON) serialization. */
    toJSON(key?: any): string;
}

Typescript可以开箱即用地识别Date接口——就像处理数字、字符串或自定义类型一样。所以就用:

myDate : Date;

正如其他人提到的，类型是Date。

当您希望在编译时强制您确实拥有一个Date对象时，此类型非常有用。下面是一个经常犯的错误(忘记new关键字)，我们可以看到它在编译时被捕获。

const date: Date = new Date();

function logDayNumber(date: Date){
    console.log(date.getDay())
} 

// Works fine
logDayNumber(date);

// Compile time error which happens when you forget new a String we be produced from Date()
// Argument of type 'string' is not assignable to parameter of type 'Date'
logDayNumber(Date());