gistfile1.txt

export const ONE_MILLISECOND: number = 1;
export const ONE_SECOND: number = ONE_MILLISECOND * 1000;
export const ONE_MINUTE: number = ONE_SECOND * 60;
export const ONE_HOUR: number = ONE_MINUTE * 60;

Date.prototype.getUTCTime = getUTCTime;
Date.prototype.isEqual = isEqual;
Date.prototype.isBefore = isBefore;
Date.prototype.isAfter = isAfter;
Date.prototype.isOnOrBefore = isOnOrBefore;
Date.prototype.isOnOrAfter = isOnOrAfter;
Date.prototype.isToday = isToday;
Date.prototype.compareTo = compareTo;

declare global {
  interface Date {

    getUTCTime: typeof getUTCTime;

    isEqual: typeof isEqual;

    isBefore: typeof isBefore;

    isAfter: typeof isAfter;

    isOnOrBefore: typeof isOnOrBefore;

    isOnOrAfter: typeof isOnOrAfter;

    isToday: typeof isToday;

    compareTo: typeof compareTo;

  }
}

export function getUTCTime(this: Date): number {
  return this.getTime() + (this.getTimezoneOffset() * 6000);
}

export function isEqual(this: Date, d: Date): boolean {
    return d && this.getUTCTime() == d.getUTCTime();
}

export function isBefore(this: Date, d: Date): boolean {
    return d && this.getUTCTime() < d.getUTCTime();
}

export function isAfter(this: Date, d: Date): boolean {
    return d && this.getUTCTime() > d.getUTCTime();
}

export function isOnOrBefore(this: Date, d: Date): boolean {
    return d && this.getUTCTime() <= d.getUTCTime();
}

export function isOnOrAfter(this: Date, d: Date): boolean {
    return d && this.getUTCTime() >= d.getUTCTime();
}

export function isToday(this: Date): boolean {
  let d: Date = new Date();
  return d.getUTCFullYear() == this.getUTCFullYear()
    && d.getUTCMonth() == this.getUTCMonth()
    && d.getUTCDate() == this.getUTCDate()
}

export function compareTo(this: Date, d: Date): number {
  let l: number = this.getUTCTime();
  let r: number = d.getUTCTime();
  if (l < r) {
    return -1;
  } else if (l > r) {
    return 1;
  }
  return 0;
}