Time
Time converter online free. Convert milliseconds, seconds, minutes, hours, days. Human-readable time format converter.
Input Value
Human Readable
1hTimeline Visualization
0h 12h 24h
4.1667% of a day
⏱️
Time Units
Milliseconds ms
3600000Seconds s
3600Minutes min
60Hours hr
1Days d
0.0417📊
Breakdown
Days
0Hours
1(remainder after days)
Minutes
0(remainder after hours)
Seconds
0(remainder after minutes)
Milliseconds
0(remainder)
Quick Reference
1 second = 1,000 ms
1 minute = 60 seconds
1 hour = 60 minutes
1 day = 24 hours
1 week = 7 days
1 year ≈ 365.25 days
Features
- Convert milliseconds, seconds, minutes, hours, days
- Human-readable time format output
- Precise decimal conversions
- Unix timestamp support
- Duration calculator
- Time unit breakdown
Common Use Cases
- Convert API timeout values (ms to seconds)
- Calculate cache expiration times
- Understand JavaScript setTimeout delays
- Convert video durations between formats
- Calculate project time estimates
Time Units and Conversions
Time units range from milliseconds (1/1000 second) to days. Understanding conversions is essential for programming, especially when working with APIs, timers, and duration calculations.
Standard Time Units:
- Millisecond (ms): 1/1000 second, used in JavaScript timing (setTimeout, Date.now())
- Second (s): Base SI unit, human-perceivable time intervals
- Minute (min): 60 seconds, short durations
- Hour (h): 60 minutes = 3600 seconds, work periods
- Day (d): 24 hours = 86,400 seconds, calendar unit
Programming Context:
- JavaScript: setTimeout/setInterval use milliseconds: setTimeout(fn, 5000) = 5 seconds
- Unix timestamp: Seconds since Jan 1, 1970 UTC (Date.now() returns ms)
- HTTP caching: max-age in seconds: Cache-Control: max-age=3600 = 1 hour
- Database intervals: Often seconds or milliseconds for precision
Common Durations:
- 1 day: 86,400 seconds = 86,400,000 milliseconds
- 1 hour: 3,600 seconds = 3,600,000 ms
- 1 minute: 60 seconds = 60,000 ms
- 1 week: 604,800 seconds = 7 days
Human-readable format: Large values are easier to understand when broken down: 3665 seconds = "1 hour, 1 minute, 5 seconds"
Examples
Valid - JavaScript setTimeout
5000ms = 5 seconds Valid - HTTP Cache Duration
86400s = 1 day Valid - Video Duration
125 minutes = 2 hours 5 minutesFrequently Asked Questions
Why does JavaScript use milliseconds for setTimeout?
Milliseconds provide precision for animations and timers. setTimeout(fn, 1000) waits 1 second. Using ms avoids decimals (1.5 seconds = 1500ms) and allows sub-second precision for smooth animations (16.67ms ≈ 60fps).
What's the difference between Date.now() and new Date()?
Date.now() returns a number (milliseconds since Unix epoch). new Date() returns a Date object with methods. Use Date.now() for timestamps and performance.now() for precise intervals (sub-millisecond accuracy).
How do I convert hours to milliseconds?
Multiply by 60 (minutes) × 60 (seconds) × 1000 (milliseconds): 1 hour = 1× 60 × 60 × 1000 = 3,600,000ms. For 24 hours: 24 × 3600000 = 86,400,000ms.
What is Unix timestamp and why use it?
Unix timestamp is seconds since Jan 1, 1970 UTC (epoch). It's timezone-independent, easy to compare/sort, and compact for storage. Most systems use it internally, then convert to local time for display.
How accurate is setTimeout in JavaScript?
setTimeout is not precise—delays can vary by 1-10ms or more depending on browser load. For critical timing (animations), use requestAnimationFrame. For precise intervals, use Web Workers or server-side timing.
💡 Tips
- For HTTP caching, use seconds: Cache-Control: max-age=86400 (1 day), max-age=3600 (1 hour)
- JavaScript: performance.now() is more accurate than Date.now() for measuring intervals
- Avoid hardcoding milliseconds—use constants: const ONE_DAY_MS = 24 * 60 * 60 * 1000;
- For human-readable durations, use libraries like date-fns or day.js instead of manual conversion