sameDate

The sameDate function checks if two dates represent the same calendar day, ignoring the time component.

Basic Usage

import { sameDate } from "cx/util";

const date1 = new Date(2024, 5, 15, 10, 30, 0);
const date2 = new Date(2024, 5, 15, 18, 45, 0);

sameDate(date1, date2); // true - same day, different times

const date3 = new Date(2024, 5, 16, 10, 30, 0);
sameDate(date1, date3); // false - different days

How It Works

The function compares only the year, month, and day components.

import { sameDate } from "cx/util";

// Same day, midnight vs end of day
const midnight = new Date(2024, 5, 15, 0, 0, 0);
const endOfDay = new Date(2024, 5, 15, 23, 59, 59);
sameDate(midnight, endOfDay); // true

// Different months
const june15 = new Date(2024, 5, 15);
const july15 = new Date(2024, 6, 15);
sameDate(june15, july15); // false

// Different years
const date2024 = new Date(2024, 5, 15);
const date2025 = new Date(2025, 5, 15);
sameDate(date2024, date2025); // false

Common Use Cases

Highlighting Today

import { sameDate } from "cx/util";

function isToday(date: Date): boolean {
  return sameDate(date, new Date());
}

// In a calendar component
const dates = generateMonthDates(currentMonth);
dates.forEach((date) => {
  if (isToday(date)) {
    // Highlight this date
  }
});

Grouping Events by Date

import { sameDate } from "cx/util";

interface Event {
  title: string;
  date: Date;
}

function groupEventsByDate(events: Event[]): Map<string, Event[]> {
  const groups = new Map<string, Event[]>();

  events.forEach((event) => {
    const dateKey = event.date.toDateString();
    if (!groups.has(dateKey)) {
      groups.set(dateKey, []);
    }
    groups.get(dateKey)!.push(event);
  });

  return groups;
}

function getEventsForDate(events: Event[], date: Date): Event[] {
  return events.filter((event) => sameDate(event.date, date));
}

API

function sameDate(d1: Date, d2: Date): boolean;

Returns: true if both dates represent the same calendar day.