formatDate fixed

Better date format
2025-08-01 11:06:07 -04:00 · 2025-08-01 09:54:22 -04:00
5 changed files with 114 additions and 100 deletions
--- a/index.html
+++ b/index.html
@ -1,9 +1,11 @@
 <html>
 	<body>
 		<script type="module">
-			import {PE} from './dist/index.mjs';
+			import {formatDate} from './dist/index.mjs';

-			console.log('data/Ts:n', PE`${'data/Ts'}:n`.methods);
+			const dt = new Date('2021-03-03T09:00:00Z');
+			const result = formatDate('Do MMMM dddd', dt, 0);
+			console.log(result);
 		</script>
 	</body>
 </html>
--- a/package.json
+++ b/package.json
@ -1,6 +1,6 @@
 {
 	"name": "@ztimson/utils",
-	"version": "0.26.26",
+	"version": "0.27.0",
 	"description": "Utility library",
 	"author": "Zak Timson",
 	"license": "MIT",
--- a/src/math.ts
+++ b/src/math.ts
@ -48,3 +48,17 @@ export function fracToDec(frac: string) {
 	split = (<string>split.pop()).split('/');
 	return whole + (Number(split[0]) / Number(split[1]));
 }
+
+/**
+ * Add a suffix to a number:
+ * 1 = 1st
+ * 2 = 2nd
+ * 3 = 3rd
+ * N = Nth
+ * @param {number} n
+ * @returns {string}
+ */
+export function numSuffix(n: number): string {
+	const s = ['th', 'st', 'nd', 'rd'], v = n % 100;
+	return `${n}${s[(v - 20) % 10] || s[v] || s[0]}`;
+}
--- a/src/time.ts
+++ b/src/time.ts
@ -1,3 +1,5 @@
+import {numSuffix} from './math.ts';
+
 /**
 * Like setInterval but will adjust the timeout value to account for runtime
 * @param {Function} cb Callback function that will be ran
@ -20,6 +22,15 @@ export function adjustedInterval(cb: Function, ms: number) {
 	}
 }

+export function dayOfWeek(d: number): string {
+	return ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'][d];
+}
+
+export function dayOfYear(date: Date): number {
+	const start = new Date(Date.UTC(date.getUTCFullYear(), 0, 1));
+	return Math.ceil((date.getTime() - start.getTime()) / (1000 * 60 * 60 * 24));
+}
+
 /**
 * Format date
 *
@ -28,111 +39,94 @@ export function adjustedInterval(cb: Function, ms: number) {
 * @param tz Set timezone offset
 * @return {string} Formated date
 */
-export function formatDate(format = 'YYYY-MM-DD H:mm', date: Date | number | string = new Date(), tz?: string | number): string {
-	const timezones = [
-		['IDLW', -12],
-		['SST', -11],
-		['HST', -10],
-		['AKST', -9],
-		['PST', -8],
-		['MST', -7],
-		['CST', -6],
-		['EST', -5],
-		['AST', -4],
-		['BRT', -3],
-		['MAT', -2],
-		['AZOT', -1],
-		['UTC', 0],
-		['CET', 1],
-		['EET', 2],
-		['MSK', 3],
-		['AST', 4],
-		['PKT', 5],
-		['IST', 5.5],
-		['BST', 6],
-		['ICT', 7],
-		['CST', 8],
-		['JST', 9],
-		['AEST', 10],
-		['SBT', 11],
-		['FJT', 12],
-		['TOT', 13],
-		['LINT', 14]
-	];
+export function formatDate(format: string = 'YYYY-MM-DD H:mm', date: Date | number | string = new Date(), tz: string | number = 'local'): string {
+	if (typeof date === 'number' || typeof date === 'string') date = new Date(date);
+	if (isNaN(date.getTime())) throw new Error('Invalid date input');
+	const numericTz = typeof tz === 'number';
+	const localTz = tz === 'local' || (!numericTz && tz.toLowerCase?.() === 'local');
+	const tzName = localTz ? Intl.DateTimeFormat().resolvedOptions().timeZone : numericTz ? 'UTC' : tz;

-	function adjustTz(date: Date, gmt: number) {
-		const currentOffset = date.getTimezoneOffset();
-		const adjustedOffset = gmt * 60;
-		return new Date(date.getTime() + (adjustedOffset + currentOffset) * 60000);
-	}
-
-	function day(num: number): string {
-		return ['Sunday', 'Monday', 'Tuesday', 'Wednesday', 'Thursday', 'Friday', 'Saturday'][num] || 'Unknown';
-	}
-
-	function doy(date: Date) {
-		const start = new Date(`${date.getFullYear()}-01-01 0:00:00`);
-		return Math.ceil((date.getTime() - start.getTime()) / (1000 * 60 * 60 * 24));
-	}
-
-	function month(num: number): string {
-		return ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'][num] || 'Unknown';
-	}
-
-	function suffix(num: number) {
-		if (num % 100 >= 11 && num % 100 <= 13) return `${num}th`;
-		switch (num % 10) {
-			case 1: return `${num}st`;
-			case 2: return `${num}nd`;
-			case 3: return `${num}rd`;
-			default: return `${num}th`;
+	if (!numericTz && tzName !== 'UTC') {
+		try {
+			new Intl.DateTimeFormat('en-US', { timeZone: tzName }).format();
+		} catch {
+			throw new Error(`Invalid timezone: ${tzName}`);
 		}
 	}

-	function tzOffset(offset: number) {
-		const hours = ~~(offset / 60);
-		const minutes = offset % 60;
-		return (offset > 0 ? '-' : '') + `${hours}:${minutes.toString().padStart(2, '0')}`;
+	let zonedDate = new Date(date);
+	if (!numericTz && tzName !== 'UTC') {
+		const parts = new Intl.DateTimeFormat('en-US', {
+			timeZone: tzName,
+			year: 'numeric', month: '2-digit', day: '2-digit',
+			hour: '2-digit', minute: '2-digit', second: '2-digit',
+			hour12: false
+		}).formatToParts(date);
+		const get = (type: string) => parts.find(p => p.type === type)?.value;
+		const build = `${get('year')}-${get('month')}-${get('day')}T${get('hour')}:${get('minute')}:${get('second')}Z`;
+		zonedDate = new Date(build);
+	} else if (numericTz || tzName === 'UTC') {
+		const offset = numericTz ? tz as number : 0;
+		zonedDate = new Date(date.getTime() + offset * 60 * 60 * 1000);
 	}

-	if(typeof date == 'number' || typeof date == 'string' || date == null) date = new Date(date);
+	const get = (fn: 'FullYear' | 'Month' | 'Date' | 'Day' | 'Hours' | 'Minutes' | 'Seconds' | 'Milliseconds') =>
+		(numericTz || tzName === 'UTC') ? zonedDate[`getUTC${fn}`]() : zonedDate[`get${fn}`]();

-	// Handle timezones
-	let t!: [string, number];
-	if(tz == null) tz = -(date.getTimezoneOffset() / 60);
-	t = <any>timezones.find(t => isNaN(<any>tz) ? t[0] == tz : t[1] == tz);
-	if(!t) throw new Error(`Unknown timezone: ${tz}`);
-	date = adjustTz(date, t[1]);
+	function getTZOffset(): string {
+		if (numericTz) {
+			const total = (tz as number) * 60;
+			const hours = Math.floor(Math.abs(total) / 60);
+			const mins = Math.abs(total) % 60;
+			return `${tz >= 0 ? '+' : '-'}${String(hours).padStart(2, '0')}:${String(mins).padStart(2, '0')}`;
+		}
+		try {
+			const offset = new Intl.DateTimeFormat('en-US', {timeZone: tzName, timeZoneName: 'longOffset', hour: '2-digit', minute: '2-digit',})
+				.formatToParts(<Date>date).find(p => p.type === 'timeZoneName')?.value.match(/([+-]\d{2}:\d{2})/)?.[1];
+			if (offset) return offset;
+		} catch {}
+		return '+00:00';
+	}
+
+	function getTZAbbr(): string {
+		if (numericTz && tz === 0) return 'UTC';
+		try {
+			return new Intl.DateTimeFormat('en-US', { timeZone: tzName, timeZoneName: 'short' })
+				.formatToParts(<Date>date).find(p => p.type === 'timeZoneName')?.value || '';
+		} catch {
+			return tzName;
+		}
+	}

-	// Token mapping
 	const tokens: Record<string, string> = {
-		'YYYY': date.getFullYear().toString(),
-		'YY': date.getFullYear().toString().slice(2),
-		'MMMM': month(date.getMonth()),
-		'MMM': month(date.getMonth()).slice(0, 3),
-		'MM': (date.getMonth() + 1).toString().padStart(2, '0'),
-		'M': (date.getMonth() + 1).toString(),
-		'DDD': doy(date).toString(),
-		'DD': date.getDate().toString().padStart(2, '0'),
-		'Do': suffix(date.getDate()),
-		'D': date.getDate().toString(),
-		'dddd': day(date.getDay()),
-		'ddd': day(date.getDay()).slice(0, 3),
-		'HH': date.getHours().toString().padStart(2, '0'),
-		'H': date.getHours().toString(),
-		'hh': (date.getHours() % 12 || 12).toString().padStart(2, '0'),
-		'h': (date.getHours() % 12 || 12).toString(),
-		'mm': date.getMinutes().toString().padStart(2, '0'),
-		'm': date.getMinutes().toString(),
-		'ss': date.getSeconds().toString().padStart(2, '0'),
-		's': date.getSeconds().toString(),
-		'SSS': date.getMilliseconds().toString().padStart(3, '0'),
-		'A': date.getHours() >= 12 ? 'PM' : 'AM',
-		'a': date.getHours() >= 12 ? 'pm' : 'am',
-		'ZZ': tzOffset(t[1] * 60).replace(':', ''),
-		'Z': tzOffset(t[1] * 60),
-		'z': typeof tz == 'string' ? tz : (<any>t)[0]
+		YYYY: get('FullYear').toString(),
+		YY: get('FullYear').toString().slice(2),
+		MMMM: month(get('Month')),
+		MMM: month(get('Month')).slice(0, 3),
+		MM: (get('Month') + 1).toString().padStart(2, '0'),
+		M: (get('Month') + 1).toString(),
+		DDD: dayOfYear(zonedDate).toString(),
+		DD: get('Date').toString().padStart(2, '0'),
+		Do: numSuffix(get('Date')),
+		D: get('Date').toString(),
+		dddd: dayOfWeek(get('Day')),
+		ddd: dayOfWeek(get('Day')).slice(0, 3),
+		HH: get('Hours').toString().padStart(2, '0'),
+		H: get('Hours').toString(),
+		hh: (get('Hours') % 12 || 12).toString().padStart(2, '0'),
+		h: (get('Hours') % 12 || 12).toString(),
+		mm: get('Minutes').toString().padStart(2, '0'),
+		m: get('Minutes').toString(),
+		ss: get('Seconds').toString().padStart(2, '0'),
+		s: get('Seconds').toString(),
+		SSS: get('Milliseconds').toString().padStart(3, '0'),
+		A: get('Hours') >= 12 ? 'PM' : 'AM',
+		a: get('Hours') >= 12 ? 'pm' : 'am',
+		ZZ: getTZOffset().replace(':', ''),
+		Z: getTZOffset(),
+		z: getTZAbbr(),
 	};
+
 	return format.replace(/YYYY|YY|MMMM|MMM|MM|M|DDD|DD|Do|D|dddd|ddd|HH|H|hh|h|mm|m|ss|s|SSS|A|a|ZZ|Z|z/g, token => tokens[token]);
 }

@ -148,6 +142,10 @@ export function instantInterval(fn: () => any, interval: number) {
 	return setInterval(fn, interval);
 }

+export function month(m: number): string {
+	return ['January', 'February', 'March', 'April', 'May', 'June', 'July', 'August', 'September', 'October', 'November', 'December'][m];
+}
+
 /**
 * Use in conjunction with `await` to pause an async script
 *
--- a/tests/time.spec.ts
+++ b/tests/time.spec.ts
@ -31,11 +31,11 @@ describe('Time Utilities', () => {
 		it('handles formatting for given timestamp', () => {
 			const timestamp = Date.UTC(2023, 1, 1, 18, 5, 5, 123); // Feb 1, 2023 18:05:05.123 UTC
 			const formatted = formatDate('YYYY MM DD HH mm ss SSS A Z', timestamp, 'UTC');
-			expect(formatted).toMatch(/^2023 02 01 18 05 05 123 PM \+?0:00$/i);
+			expect(formatted).toMatch(/^2023 02 01 18 05 05 123 PM \+00:00/i);
 		});

 		it('throws for unknown timezone', () => {
-			expect(() => formatDate('YYYY', new Date(), '???')).toThrowError(/Unknown timezone/);
+			expect(() => formatDate('YYYY', new Date(), '???')).toThrowError(/Invalid timezone/);
 		});

 		it('handles timezone by offset number', () => {
Author	SHA1	Message	Date
ztimson	31998c01d6	formatDate fixed Some checks failed Build / Build NPM Project (push) Successful in 1m12s Details Build / Tag Version (push) Successful in 16s Details Build / Publish Documentation (push) Failing after 16s Details	2025-08-01 11:06:07 -04:00
ztimson	c5270fbd7e	Better date format Some checks failed Build / Build NPM Project (push) Failing after 46s Details Build / Publish Documentation (push) Has been skipped Details Build / Tag Version (push) Has been skipped Details	2025-08-01 09:54:22 -04:00