Run results for: new Intl.DateTimeFormat vs no new Intl.DateTimeFormat

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/135.0.0.0 Safari/537.36

Browser: Chrome 135

Operating system: Windows

Device Platform: Desktop

Date tested: yesterday

Test name	Executions per second
new Intl.DateTimeFormat.format()	17907.7 Ops/sec
Intl.DateTimeFormat.format()	17730.5 Ops/sec
new Intl.DateTimeFormat.formatToParts	17823.8 Ops/sec
Intl.DateTimeFormat.formatToParts	17882.4 Ops/sec

Script Preparation code:

const TWO_DIGIT = '2-digit';

var options = {
      month: TWO_DIGIT,
      year: 'numeric',
      day: TWO_DIGIT,
      hour: TWO_DIGIT,
      hour12: false,
      minute: TWO_DIGIT,
      second: TWO_DIGIT,
    }

var cached = new Intl.DateTimeFormat('en-US', options);

Tests:

new Intl.DateTimeFormat.format()
new Intl.DateTimeFormat('en-US', options).format(new Date());
Intl.DateTimeFormat.format()
Intl.DateTimeFormat('en-US', options).format(new Date());
new Intl.DateTimeFormat.formatToParts
new Intl.DateTimeFormat('en-US', options).formatToParts(new Date());
Intl.DateTimeFormat.formatToParts
Intl.DateTimeFormat('en-US', options).formatToParts(new Date());

Run results for: new Intl.DateTimeFormat vs no new Intl.DateTimeFormat

measure the perf impact of caching calls to new Intl.DateTimeFormat

new Intl.DateTimeFormat.format()

Intl.DateTimeFormat.format()

new Intl.DateTimeFormat.formatToParts

Intl.DateTimeFormat.formatToParts