Run results for: Date JS VS Date-Fns VS MomentJS - startOfDay

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:141.0) Gecko/20100101 Firefox/141.0

Browser: Firefox 141

Operating system: Windows

Device Platform: Desktop

Date tested: 9 months ago

Test name	Executions per second
Date JS	7551611.0 Ops/sec
Date-Fns	5713305.5 Ops/sec
MomentJS	919386.4 Ops/sec

HTML Preparation code:

<script src="https://cdn.jsdelivr.net/npm/moment@2.29.4/moment.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/date-fns/cdn.min.js"></script>

Script Preparation code:

var unix = 1724409214;

Tests:

Date JS
const now = new Date(); const startOfDayUTC = new Date(now); startOfDayUTC.setUTCHours(0, 0, 0, 0); const isoString = startOfDayUTC.toISOString();
Date-Fns
const now = new Date(); const startOfDayUTC = dateFns.startOfDay(now); const isoString = startOfDayUTC.toISOString();
MomentJS
const isoString = moment().utc().startOf('day').toISOString();