@heyhru/common-util-timezone

User-timezone-aware date utilities built on Intl.DateTimeFormat. No external dependencies. Works in Node.js, browser, and React Native.

Usage

import {
  USER_TZ,
  tzParts,
  tzStartOfDay,
  tzDateKey,
  tzWeekday,
  tzTimeHHMM,
  tzShortDate,
  tzDayRange,
} from "@heyhru/common-util-timezone";

// "America/New_York" | "Asia/Shanghai" | ...
console.log(USER_TZ);

// Break a timestamp into local date parts
const parts = tzParts(Date.now());
// { year, month, day, hour, minute, second, weekday }

// 00:00:00 of the day in user's timezone (DST-safe)
const startMs = tzStartOfDay(Date.now());

// "2024.03.15"
const key = tzDateKey(Date.now());

// 0 (Sun) … 6 (Sat)
const wd = tzWeekday(Date.now());

// "9:05"
const hhmm = tzTimeHHMM(Date.now());

// "Mar 15"
const short = tzShortDate(Date.now());

// { startSec, endSec } — unix seconds for the full day
const range = tzDayRange("2024.03.15");

API

| Export | Description | |---|---| | USER_TZ | User's IANA timezone string | | tzParts(ms) | Break timestamp into TzParts in user timezone | | tzStartOfDay(ms) | Unix ms for 00:00:00 of the day (DST-safe) | | tzDateKey(ms) | Format as "YYYY.MM.DD" | | tzWeekday(ms) | Weekday number 0(Sun)–6(Sat) | | tzTimeHHMM(ms) | Format as "H:MM" | | tzShortDate(ms) | Format as "Mar 5" | | tzDayRange(dateKey) | { startSec, endSec } for a "YYYY.MM.DD" key |