Date format like java SimpleDateFormat

var dateFormat = new SimpleDateFormat('yyyy-MM-dd HH:mm:ss');
var date1 = new Date(2000,1,1,1,1,1,999);
assert.strictEqual(dateFormat.format(date1),"2000-02-01 01:01:01");

var dateFormat = new SimpleDateFormat('yyyy-MM-dd HH:mm:ss');
var date1 = new Date(2000,1,1,1,1,1);
assert.strictEqual(dateFormat.parse("2000-02-01 01:01:01").getTime(),date1.getTime());

Supported pattern letters

| Letter | Meaning | Example | |--------|--------------------|-----------------| | y | Year | yy → 25, yyyy → 2025 | | M | Month | M → 6, MM → 06 | | d | Day in month | d → 1, dd → 01 | | H | Hour (0-23) | H → 9, HH → 09 | | h | Hour (1-12) | h → 9, hh → 09 | | m | Minute | m → 5, mm → 05 | | s | Second | s → 3, ss → 03 | | S | Millisecond | S → 9, SSS → 009 | | a | AM/PM marker | AM, PM |

Quoting and escaping

Like Java's SimpleDateFormat, single quotes can be used to quote literal text:

var dateFormat = new SimpleDateFormat("'Date:' yyyy-MM-dd");
dateFormat.format(new Date(2025, 5, 16)); // "Date: 2025-06-16"

Two consecutive single quotes produce a literal single quote:

var dateFormat = new SimpleDateFormat("hh''mm");
dateFormat.format(new Date(2000, 0, 1, 9, 5)); // "09'05"

Inside quoted text, use '' to escape a single quote:

var dateFormat = new SimpleDateFormat("'it''s' yyyy");
dateFormat.format(new Date(2025, 0, 1)); // "it's 2025"

CJK characters as literals:

var dateFormat = new SimpleDateFormat("yyyy'年'MM'月'dd'日'");
dateFormat.format(new Date(2025, 5, 16)); // "2025年06月16日"

12-hour time with AM/PM

var dateFormat = new SimpleDateFormat('hh:mm a');
dateFormat.format(new Date(2000, 0, 1, 0, 0));  // "12:00 AM" (midnight)
dateFormat.format(new Date(2000, 0, 1, 12, 0)); // "12:00 PM" (noon)
dateFormat.format(new Date(2000, 0, 1, 13, 5)); // "01:05 PM"

Not supported

• Y (week year) - a common pitfall in Java, intentionally not implemented
• D (day in year) - a common pitfall in Java, intentionally not implemented
• E (day name), G (era), w/W (week), F, k, K, z, Z, X (timezone)