datetimeBenchmark.ts

import Benchmark from "benchmark";

const datetimeValidationSuite = new Benchmark.Suite("datetime");

const DATA = "2020-01-01";
const MONTHS_31 = new Set([1, 3, 5, 7, 8, 10, 12]);
const MONTHS_30 = new Set([4, 6, 9, 11]);

const simpleDatetimeRegex = /^(\d{4})-(\d{2})-(\d{2})$/;
const datetimeRegexNoLeapYearValidation =
	/^\d{4}-((0[13578]|10|12)-31|(0[13-9]|1[0-2])-30|(0[1-9]|1[0-2])-(0[1-9]|1\d|2\d))$/;
const datetimeRegexWithLeapYearValidation =
	/^((\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-((0[13578]|1[02])-(0[1-9]|[12]\d|3[01])|(0[469]|11)-(0[1-9]|[12]\d|30)|(02)-(0[1-9]|1\d|2[0-8])))$/;

datetimeValidationSuite
	.add("new Date()", () => {
		return !Number.isNaN(new Date(DATA).getTime());
	})
	.add("regex (no validation)", () => {
		return simpleDatetimeRegex.test(DATA);
	})
	.add("regex (no leap year)", () => {
		return datetimeRegexNoLeapYearValidation.test(DATA);
	})
	.add("regex (w/ leap year)", () => {
		return datetimeRegexWithLeapYearValidation.test(DATA);
	})
	.add("capture groups + code", () => {
		const match = DATA.match(simpleDatetimeRegex);
		if (!match) return false;

		// Extract year, month, and day from the capture groups
		const year = Number.parseInt(match[1], 10);
		const month = Number.parseInt(match[2], 10); // month is 0-indexed in JavaScript Date, so subtract 1
		const day = Number.parseInt(match[3], 10);

		if (month === 2) {
			if ((year % 4 === 0 && year % 100 !== 0) || year % 400 === 0) {
				return day <= 29;
			}
			return day <= 28;
		}
		if (MONTHS_30.has(month)) {
			return day <= 30;
		}
		if (MONTHS_31.has(month)) {
			return day <= 31;
		}
		return false;
	})
	.on("cycle", (e: Benchmark.Event) => {
		console.log(`${datetimeValidationSuite.name!}: ${e.target}`);
	});

datetimeValidationSuite.run();

results.sh

$ yarn tsx datetimeBenchmark.ts
datetime: new Date() x 9,671,700 ops/sec ±0.68% (97 runs sampled)
datetime: regex (no validation) x 41,566,285 ops/sec ±0.44% (94 runs sampled)
datetime: regex (no leap year) x 36,370,328 ops/sec ±0.33% (95 runs sampled)
datetime: regex (w/ leap year) x 28,522,551 ops/sec ±0.29% (95 runs sampled)
datetime: capture groups + code x 6,904,882 ops/sec ±0.28% (95 runs sampled)
✨  Done in 27.29s.