Time Conversion Table
Comprehensive reference table for converting between time and duration units. Essential for scheduling, programming, project management, and scientific applications.
| Unit | Symbol | Seconds (s) | Minutes (min) | Hours (h) | Days (d) | Weeks (wk) | Years (yr) |
|---|---|---|---|---|---|---|---|
| Nanosecond | ns | 1.000e-9 | 1.667e-11 | 2.778e-13 | 1.157e-14 | 1.653e-15 | 3.171e-17 |
| Microsecond | μs | 1.000e-6 | 1.667e-8 | 2.778e-10 | 1.157e-11 | 1.653e-12 | 3.171e-14 |
| Millisecond | ms | 0.001 | 1.667e-5 | 2.778e-7 | 1.157e-8 | 1.653e-9 | 3.171e-11 |
| Second | s | 1 | 0.0167 | 2.780e-4 | 1.157e-5 | 1.653e-6 | 3.171e-8 |
| Minute | min | 60 | 1 | 0.0167 | 6.940e-4 | 9.921e-5 | 1.903e-6 |
| Hour | h | 3,600 | 60 | 1 | 0.0417 | 0.00595 | 1.140e-4 |
| Day | d | 86,400 | 1,440 | 24 | 1 | 0.143 | 0.00274 |
| Week | wk | 604,800 | 10,080 | 168 | 7 | 1 | 0.0192 |
| Month | mo | 2.630e+6 | 43,829.1 | 730.485 | 30.437 | 4.348 | 0.0833 |
| Year | yr | 3.156e+7 | 525,949 | 8,765.82 | 365.242 | 52.178 | 1 |
Built on International Standards
This time conversion table uses ISO 80000-3 definitions and standard time units maintained by international standards bodies to ensure accuracy for engineering, scientific, and scheduling applications.
All conversion factors are cross-checked annually against ISO standards and leading scientific references to maintain precise, reliable results across milliseconds, seconds, hours, days, weeks, and years.
ISO 80000-3:2019
Defines quantities and units of space and time, ensuring consistent time unit relationships across scientific and engineering disciplines.
https://www.iso.org/standard/64973.htmlNIST Time and Frequency Division
Authoritative US reference for timekeeping standards including UTC traceability and precision measurement guidance.
https://www.nist.gov/pml/time-and-frequency-divisionIERS Bulletins
Official UTC coordination and leap second announcements that keep civil time aligned with Earth's rotation.
https://www.iers.org/IERS/EN/Home/home_node.htmlHow to Use This Time Conversion Table
Find Your Source Unit for Quick Time Calculations
Locate the time unit you want to convert from in the leftmost column. Whether you need to convert milliseconds to seconds for programming or calculate hours to days for project planning, use the search function to quickly find specific units.
Read Across for Accurate Duration Conversions
Read across the row to find the equivalent values in other time units. All conversion factors are mathematically precise and based on international standards. Perfect for converting minutes to hours in Excel or calculating seconds in a week for database queries.
Apply Time Conversions to Real-World Scheduling
Use the converted values in your programming, scheduling, or scientific applications. Common applications include calculating work hours to days, converting timestamp milliseconds to readable time, and determining billable hours in decimal format.
Verify Precision for Critical Time Measurements
Double-check critical calculations using the precise conversion factors provided. Essential when converting epoch time to hours or calculating accurate time differences for payroll systems.
Use Cases for Time Conversions
Programming & Development - Convert Milliseconds to Seconds
Convert time units for timeouts, delays, and performance measurements. Essential for system programming and application development. Learn how to convert Unix timestamp to hours, calculate milliseconds in a day for JavaScript timers, and optimize API timeout settings.
Project Management - Calculate Working Days to Hours
Calculate project durations, deadlines, and scheduling across different time units for effective project planning and tracking. Convert man-hours to days for resource allocation, calculate sprint duration in hours, and determine project timeline in weeks to months.
Scientific Research - Precise Time Unit Conversions
Convert time measurements in experiments, data analysis, and research documentation. Critical for precise scientific calculations including converting nanoseconds to microseconds for laboratory measurements and calculating half-life in various time units.
Scheduling & Planning - Convert Hours to Days for Shifts
Convert between different time units for scheduling meetings, events, and activities across international time zones. Calculate total hours in a work week, convert shift duration to decimal hours, and determine meeting length in minutes for calendar applications.
Test Your Skills
Challenge yourself with our interactive conversion game!
🤯 Mind-Blowing Comparisons
Eye Blink
100-150 ms = 0.1-0.15 seconds
100m World Record
9.58 seconds = 0.16 minutes
Average Movie
2 hours = 120 minutes = 7,200 seconds
Earth Rotation
24 hours = 1,440 minutes = 86,400 seconds
Time Conversion FAQ
How many seconds are in a day exactly?
There are exactly 86,400 seconds in a day (24 × 60 × 60). Essential for programming time-based functions, calculating daily rates, and understanding Unix timestamps.
How do I convert milliseconds to seconds in Excel?
Divide by 1,000. Example: if A1=5000, =A1/1000 returns 5 seconds. Divide by 60 to move from seconds to minutes.
What is the easiest way to calculate hours to days for payroll?
Divide total hours by your standard workday (often 8). Example: 40 ÷ 8 = 5 working days. For decimal hours, 7.5 hours = 0.9375 days on an 8-hour system.
How many minutes in a work week for scheduling?
2,400 minutes in a 40-hour week (480 minutes per 8-hour day). Useful for meetings, shift planning, and time tracking.
How to convert Unix timestamp to readable time?
Divide by 86,400 for days or 3,600 for hours. Example: 1,609,459,200 ÷ 86,400 = 18,628 days since epoch = Jan 1, 2021.
What's the difference between calendar year and leap year in seconds?
Calendar year: 31,536,000 seconds (365 days). Leap year: 31,622,400 seconds (366 days). Difference: 86,400 seconds (1 extra day).
How do I convert microseconds to milliseconds for programming?
Divide by 1,000. Example: 5,000 microseconds = 5 milliseconds—common in performance monitoring and latency tracking.
How many hours in a month for project planning?
Average month ≈ 730 hours (30.42 days). Standard work month ≈ 160 hours (40 hours/week × 4 weeks).
How to calculate billable hours in decimal format?
decimal hours = hours + (minutes ÷ 60). Example: 2h 30m = 2.5 hours; 15-minute increments multiply by 0.25.
What is the best way to convert nanoseconds to seconds in Python?
Divide by 1e9. Example: seconds = nanoseconds / 1e9. Use for high-precision timing and profiling.
How many seconds in a week for database calculations?
604,800 seconds (7 × 24 × 60 × 60). Useful for retention policies, recurring jobs, and cache expirations.
How to convert time duration between different units in JavaScript?
Use multiplication/division: ms → s (÷1000), s → min (÷60), min → h (÷60), h → d (÷24). Example: const days = ms / (1000*60*60*24);
How accurate are online time conversion calculators?
They are mathematically precise using standard factors. For astronomy, account for leap seconds and relativistic effects.
What is the formula to convert seconds to hours and minutes?
hours = seconds ÷ 3,600; minutes = (seconds % 3,600) ÷ 60. Example: 7,265 seconds = 2 hours and 1 minute.
How do I convert between 12-hour and 24-hour time format?
12→24: add 12 to PM hours (except 12 PM), 12 AM becomes 0. 24→12: subtract 12 when >12 and mark PM; 0 becomes 12 AM.