🏁 Datezone vs Date-fns Performance Comparison

Generated: 2025-07-18T11:30:21.757Z
Node.js: v24.3.0
Platform: darwin arm64

📊 Performance Overview

This report compares Datezone against Date-fns v4 with timeZone support (@date-fns/tz).

🏆 Performance Legend

Icon	Meaning	Improvement
🚀	Datezone dominates	>100% faster
⚡	Datezone wins	25-100% faster
✅	Datezone leads	10-25% faster
🤝	Close match	<10% difference
⚠️	Date-fns leads	10-25% faster
🐌	Date-fns wins	>25% faster

Day (DST)

Operation	Datezone	Date-fns	Performance
`addDays`	addDays`2.0M ops/sec`	addDays`100.0K ops/sec`	🚀 `+1890%`
`startOfDay`	startOfDay`1.5M ops/sec`	startOfDay`106.6K ops/sec`	🚀 `+1266%`
`endOfDay`	endOfDay`1.4M ops/sec`	endOfDay`108.1K ops/sec`	🚀 `+1237%`
`dayOfWeek`	dayOfWeek`1.4M ops/sec`	dayOfWeek`169.2K ops/sec`	🚀 `+751%`
`dayOfYear`	dayOfYear`9.5M ops/sec`	dayOfYear`22.5K ops/sec`	🚀 `+42010%`

Day (Local)

Operation	Datezone	Date-fns	Performance
`addDays`	addDays`7.2M ops/sec`	addDays`15.4M ops/sec`	🐌 `-53%`
`startOfDay`	startOfDay`14.9M ops/sec`	startOfDay`14.8M ops/sec`	🤝
`endOfDay`	endOfDay`13.9M ops/sec`	endOfDay`14.5M ops/sec`	🤝
`dayOfWeek`	dayOfWeek`27.6M ops/sec`	dayOfWeek`26.5M ops/sec`	🤝
`dayOfYear`	dayOfYear`8.4M ops/sec`	dayOfYear`559.5K ops/sec`	🚀 `+1410%`

Day (Non-DST)

Operation	Datezone	Date-fns	Performance
`addDays`	addDays`77.8M ops/sec`	addDays`117.5K ops/sec`	🚀 `+66105%`
`startOfDay`	startOfDay`5.4M ops/sec`	startOfDay`127.1K ops/sec`	🚀 `+4115%`
`endOfDay`	endOfDay`10.9M ops/sec`	endOfDay`127.0K ops/sec`	🚀 `+8487%`
`dayOfWeek`	dayOfWeek`23.7M ops/sec`	dayOfWeek`203.6K ops/sec`	🚀 `+11542%`
`dayOfYear`	dayOfYear`12.8M ops/sec`	dayOfYear`26.9K ops/sec`	🚀 `+47665%`

Day (UTC)

Operation	Datezone	Date-fns	Performance
`addDays`	addDays`36.3M ops/sec`	addDays`141.1K ops/sec`	🚀 `+25659%`
`startOfDay`	startOfDay`9.6M ops/sec`	startOfDay`155.6K ops/sec`	🚀 `+6096%`
`endOfDay`	endOfDay`9.0M ops/sec`	endOfDay`155.7K ops/sec`	🚀 `+5685%`
`dayOfWeek`	dayOfWeek`19.0M ops/sec`	dayOfWeek`253.5K ops/sec`	🚀 `+7404%`
`dayOfYear`	dayOfYear`9.8M ops/sec`	dayOfYear`32.8K ops/sec`	🚀 `+29679%`

Duration (DST)

Operation	Datezone	Date-fns	Performance
`intervalToDuration`	intervalToDuration`1.2M ops/sec`	intervalToDuration`30.3K ops/sec`	🚀 `+3807%`

Duration (Local)

Operation	Datezone	Date-fns	Performance
`intervalToDuration`	intervalToDuration`5.6M ops/sec`	intervalToDuration`693.3K ops/sec`	🚀 `+708%`

Duration (Non-DST)

Operation	Datezone	Date-fns	Performance
`intervalToDuration`	intervalToDuration`3.7M ops/sec`	intervalToDuration`35.8K ops/sec`	🚀 `+10147%`

Duration (UTC)

Operation	Datezone	Date-fns	Performance
`intervalToDuration`	intervalToDuration`5.2M ops/sec`	intervalToDuration`43.1K ops/sec`	🚀 `+12039%`

Format (DST)

Operation	Datezone	Date-fns	Performance
`format`	format`513.8K ops/sec`	format`71.4K ops/sec`	🚀 `+620%`

Format (Local)

Operation	Datezone	Date-fns	Performance
`format`	format`614.9K ops/sec`	format`210.0K ops/sec`	🚀 `+193%`

Format (Non-DST)

Operation	Datezone	Date-fns	Performance
`format`	format`561.5K ops/sec`	format`77.4K ops/sec`	🚀 `+625%`

Format (UTC)

Operation	Datezone	Date-fns	Performance
`format`	format`701.0K ops/sec`	format`86.7K ops/sec`	🚀 `+709%`

Format-duration (DST)

Operation	Datezone	Date-fns	Performance
`formatDuration`	formatDuration`411.4K ops/sec`	formatDuration`516.3K ops/sec`	⚠️ `-20%`
`formatDuration complex`	formatDuration complex`184.6K ops/sec`	formatDuration complex`380.3K ops/sec`	🐌 `-51%`
`formatDuration zero values`	formatDuration zero values`500.5K ops/sec`	formatDuration zero values`497.8K ops/sec`	🤝

Format-duration (Local)

Operation	Datezone	Date-fns	Performance
`formatDuration`	formatDuration`9.4M ops/sec`	formatDuration`498.6K ops/sec`	🚀 `+1787%`
`formatDuration complex`	formatDuration complex`4.0M ops/sec`	formatDuration complex`402.6K ops/sec`	🚀 `+884%`
`formatDuration with locale`	formatDuration with locale`9.1M ops/sec`	formatDuration with locale`507.3K ops/sec`	🚀 `+1684%`

Format-duration (Non-DST)

Operation	Datezone	Date-fns	Performance
`formatDuration`	formatDuration`523.1K ops/sec`	formatDuration`499.1K ops/sec`	🤝
`formatDuration complex`	formatDuration complex`222.8K ops/sec`	formatDuration complex`375.7K ops/sec`	🐌 `-41%`
`formatDuration with delimiter`	formatDuration with delimiter`613.2K ops/sec`	formatDuration with delimiter`512.2K ops/sec`	✅ `+20%`

Format-duration (UTC)

Operation	Datezone	Date-fns	Performance
`formatDuration`	formatDuration`8.5M ops/sec`	formatDuration`506.3K ops/sec`	🚀 `+1585%`
`formatDuration complex`	formatDuration complex`3.8M ops/sec`	formatDuration complex`407.6K ops/sec`	🚀 `+840%`
`formatDuration custom format`	formatDuration custom format`9.2M ops/sec`	formatDuration custom format`856.6K ops/sec`	🚀 `+974%`

Hour (DST)

Operation	Datezone	Date-fns	Performance
`hour`	hour`8.0M ops/sec`	hour`280.5K ops/sec`	🚀 `+2757%`
`addHours`	addHours`5081.9M ops/sec`	addHours`108.3K ops/sec`	🚀 `+4690406%`

Hour (Local)

Operation	Datezone	Date-fns	Performance
`hour`	hour`12.1M ops/sec`	hour`36.3M ops/sec`	🐌 `-67%`
`addHours`	addHours`2727.8M ops/sec`	addHours`8.0M ops/sec`	🚀 `+34191%`

Hour (Non-DST)

Operation	Datezone	Date-fns	Performance
`hour`	hour`9.3M ops/sec`	hour`372.9K ops/sec`	🚀 `+2381%`
`addHours`	addHours`5088.1M ops/sec`	addHours`135.6K ops/sec`	🚀 `+3752980%`

Hour (UTC)

Operation	Datezone	Date-fns	Performance
`hour`	hour`220.8M ops/sec`	hour`373.4K ops/sec`	🚀 `+59029%`
`addHours`	addHours`5115.9M ops/sec`	addHours`163.3K ops/sec`	🚀 `+3133484%`

Iso (DST)

Operation	Datezone	Date-fns	Performance
`toISOString`	toISOString`1.6M ops/sec`	toISOString`118.9K ops/sec`	🚀 `+1282%`
`fromISOString`	fromISOString`32.1M ops/sec`	fromISOString`844.9K ops/sec`	🚀 `+3699%`

Iso (Local)

Operation	Datezone	Date-fns	Performance
`toISOString`	toISOString`2.6M ops/sec`	toISOString`1.7M ops/sec`	⚡ `+47%`
`fromISOString`	fromISOString`32.3M ops/sec`	fromISOString`694.0K ops/sec`	🚀 `+4559%`

Iso (Non-DST)

Operation	Datezone	Date-fns	Performance
`toISOString`	toISOString`2.0M ops/sec`	toISOString`129.8K ops/sec`	🚀 `+1412%`
`fromISOString`	fromISOString`33.3M ops/sec`	fromISOString`858.0K ops/sec`	🚀 `+3779%`

Iso (UTC)

Operation	Datezone	Date-fns	Performance
`toISOString`	toISOString`7.1M ops/sec`	toISOString`175.9K ops/sec`	🚀 `+3926%`
`fromISOString`	fromISOString`34.2M ops/sec`	fromISOString`858.9K ops/sec`	🚀 `+3877%`

Month (DST)

Operation	Datezone	Date-fns	Performance
`addMonths`	addMonths`1.0M ops/sec`	addMonths`60.2K ops/sec`	🚀 `+1581%`
`startOfMonth`	startOfMonth`1.6M ops/sec`	startOfMonth`77.8K ops/sec`	🚀 `+1980%`
`endOfMonth`	endOfMonth`1.6M ops/sec`	endOfMonth`77.0K ops/sec`	🚀 `+1914%`
`daysInMonth`	daysInMonth`10.8M ops/sec`	daysInMonth`60.4K ops/sec`	🚀 `+17837%`

Month (Local)

Operation	Datezone	Date-fns	Performance
`addMonths`	addMonths`3.1M ops/sec`	addMonths`2.7M ops/sec`	✅ `+16%`
`startOfMonth`	startOfMonth`3.7M ops/sec`	startOfMonth`3.7M ops/sec`	🤝
`endOfMonth`	endOfMonth`5.2M ops/sec`	endOfMonth`5.0M ops/sec`	🤝
`daysInMonth`	daysInMonth`29.5M ops/sec`	daysInMonth`2.6M ops/sec`	🚀 `+1013%`

Month (Non-DST)

Operation	Datezone	Date-fns	Performance
`addMonths`	addMonths`4.2M ops/sec`	addMonths`69.5K ops/sec`	🚀 `+5889%`
`startOfMonth`	startOfMonth`7.1M ops/sec`	startOfMonth`89.8K ops/sec`	🚀 `+7781%`
`endOfMonth`	endOfMonth`6.8M ops/sec`	endOfMonth`91.7K ops/sec`	🚀 `+7274%`
`daysInMonth`	daysInMonth`15.2M ops/sec`	daysInMonth`73.1K ops/sec`	🚀 `+20744%`

Month (UTC)

Operation	Datezone	Date-fns	Performance
`addMonths`	addMonths`5.4M ops/sec`	addMonths`82.1K ops/sec`	🚀 `+6434%`
`startOfMonth`	startOfMonth`6.5M ops/sec`	startOfMonth`108.9K ops/sec`	🚀 `+5835%`
`endOfMonth`	endOfMonth`6.2M ops/sec`	endOfMonth`107.0K ops/sec`	🚀 `+5657%`
`daysInMonth`	daysInMonth`12.7M ops/sec`	daysInMonth`87.1K ops/sec`	🚀 `+14510%`

Week (DST)

Operation	Datezone	Date-fns	Performance
`addWeeks`	addWeeks`1.2M ops/sec`	addWeeks`101.4K ops/sec`	🚀 `+1061%`
`startOfWeek`	startOfWeek`1.5M ops/sec`	startOfWeek`77.0K ops/sec`	🚀 `+1823%`
`endOfWeek`	endOfWeek`1.6M ops/sec`	endOfWeek`78.8K ops/sec`	🚀 `+1944%`

Week (Local)

Operation	Datezone	Date-fns	Performance
`addWeeks`	addWeeks`6636.4M ops/sec`	addWeeks`6.0M ops/sec`	🚀 `+110831%`
`startOfWeek`	startOfWeek`3.2M ops/sec`	startOfWeek`3.0M ops/sec`	🤝
`endOfWeek`	endOfWeek`6.5M ops/sec`	endOfWeek`5.5M ops/sec`	✅ `+18%`

Week (Non-DST)

Operation	Datezone	Date-fns	Performance
`addWeeks`	addWeeks`4.9M ops/sec`	addWeeks`116.6K ops/sec`	🚀 `+4139%`
`startOfWeek`	startOfWeek`7.8M ops/sec`	startOfWeek`89.8K ops/sec`	🚀 `+8539%`
`endOfWeek`	endOfWeek`7.5M ops/sec`	endOfWeek`92.1K ops/sec`	🚀 `+8081%`

Week (UTC)

Operation	Datezone	Date-fns	Performance
`addWeeks`	addWeeks`6.1M ops/sec`	addWeeks`136.5K ops/sec`	🚀 `+4384%`
`startOfWeek`	startOfWeek`6.1M ops/sec`	startOfWeek`105.3K ops/sec`	🚀 `+5691%`
`endOfWeek`	endOfWeek`5.9M ops/sec`	endOfWeek`110.0K ops/sec`	🚀 `+5301%`

Year (DST)

Operation	Datezone	Date-fns	Performance
`addYears`	addYears`4.6M ops/sec`	addYears`59.9K ops/sec`	🚀 `+7526%`
`startOfYear`	startOfYear`1.5M ops/sec`	startOfYear`74.7K ops/sec`	🚀 `+1944%`
`endOfYear`	endOfYear`1.2M ops/sec`	endOfYear`74.3K ops/sec`	🚀 `+1515%`
`year`	year`17.4M ops/sec`	year`353.3K ops/sec`	🚀 `+4825%`

Year (Local)

Operation	Datezone	Date-fns	Performance
`addYears`	addYears`3.1M ops/sec`	addYears`2.8M ops/sec`	✅ `+12%`
`startOfYear`	startOfYear`9.5M ops/sec`	startOfYear`3.5M ops/sec`	🚀 `+168%`
`endOfYear`	endOfYear`9.3M ops/sec`	endOfYear`3.6M ops/sec`	🚀 `+160%`
`year`	year`28.0M ops/sec`	year`29.1M ops/sec`	🤝

Year (Non-DST)

Operation	Datezone	Date-fns	Performance
`addYears`	addYears`5.1M ops/sec`	addYears`69.5K ops/sec`	🚀 `+7204%`
`startOfYear`	startOfYear`8.0M ops/sec`	startOfYear`90.2K ops/sec`	🚀 `+8772%`
`endOfYear`	endOfYear`7.9M ops/sec`	endOfYear`89.6K ops/sec`	🚀 `+8726%`
`year`	year`23.7M ops/sec`	year`423.0K ops/sec`	🚀 `+5497%`

Year (UTC)

Operation	Datezone	Date-fns	Performance
`addYears`	addYears`8.3M ops/sec`	addYears`81.0K ops/sec`	🚀 `+10094%`
`startOfYear`	startOfYear`7.8M ops/sec`	startOfYear`107.1K ops/sec`	🚀 `+7218%`
`endOfYear`	endOfYear`7.8M ops/sec`	endOfYear`107.5K ops/sec`	🚀 `+7140%`
`year`	year`19.3M ops/sec`	year`530.5K ops/sec`	🚀 `+3537%`

📈 Summary

Metric	Count	Percentage
Datezone wins	`86`	`86.0%`
Date-fns wins	`5`	`5.0%`
Close matches	`9`	`9.0%`

🔬 Methodology

Benchmark Setup

Tool: Mitata - High-precision JavaScript benchmarking
Iterations: Multiple samples with statistical significance testing
Environment: Node.js v24.3.0 on darwin arm64

Comparison Approach

Datezone: Built-in timeZone support with UTC timestamps
Date-fns: v4.x with @date-fns/tz package for timeZone operations
Test Data: Realistic timestamps across different times and timezones
Fairness: Both libraries tested with equivalent timeZone-aware operations

Performance Metrics

Time (avg): Average execution time per operation
Operations/sec: Throughput (higher = better)
Comparison: Based on operations per second difference

Test Categories

Local: Standard local time operations
UTC: Optimized UTC timeZone operations
Non-DST: Fixed offset timeZones (fastest timeZone path)
DST: Complex DST-aware timeZone operations

Notes

Results may vary based on system specifications and load
Benchmarks focus on equivalent functionality where available
Some operations are unique to Datezone (timeZone utilities)
All operations tested with timeZone awareness for fair comparison
Non-DST timeZones should show the best performance for timeZone-aware operations

🛠️ How to Regenerate This Report

To regenerate this comparison report, run:

bun run bench --json
bun run tools/benchmark/create-comparison-report.ts

This will update tools/benchmark/reports/comparison-report.md.

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