Run results for: Date loops

Run details:

User agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/26.3 Safari/605.1.15

Browser: Safari 26

Operating system: Mac OS X 10.15.7

Device Platform: Desktop

Date tested: 4 months ago

Not parsed

450/s

Parsed

268/s

View exact numbers

Test name	Executions per second
✓ Not parsed	450 Ops/sec
Parsed	268 Ops/sec

Script Preparation code:

let periods = Array.from({length: 10000}).map((_,idx) => ({start: new Date(1000 * idx).toISOString() , end: new Date(1000 * idx + 500).toISOString()}))

Tests:

Parsed
const parsed = periods.map(p => ({ start: new Date(p.start), end: new Date(p.end) })); const merged = [parsed[0]]; for (let i = 1; i < parsed.length; i++) { const last = merged[merged.length - 1]; if (last.end >= parsed[i].start) { last.end = new Date(Math.max(last.end, parsed[i].end)); } else { merged.push(parsed[i]); } } merged.forEach(p => p.end = p.end.toISOString()); periods = merged;
Not parsed
if (periods.length > 1) { const merged = [ periods[0] ]; for (let i = 1; i < periods.length; i++) { const last = merged[merged.length - 1]; if (new Date(last.end) >= new Date(periods[i].start)) { last.end = new Date(Math.max(new Date(last.end), new Date(periods[i].end))).toISOString(); } else { merged.push(periods[i]); } } periods = merged; }