Time Converter
Convert time units instantly — seconds, minutes, hours, days, weeks, months, and years. Simple and accurate online time unit converter for everyday and scientific use.
Understanding Time Measurements
Time measures the progression of events from past to future. The second serves as the SI base unit for time, defined by the vibration of cesium-133 atoms. You use time measurements constantly — scheduling meetings, tracking project deadlines, cooking meals, or planning travel.
Time units follow a mixed base system. Sixty seconds make a minute, sixty minutes make an hour, twenty-four hours make a day. This sexagesimal system originated with ancient Babylonians. Weeks, months, and years connect to astronomical cycles — Earth's rotation, Moon's orbit, and Earth's journey around the Sun.
Time Conversion Formulas
Hours to Minutes
minutes = hours × 60
Example: 2.5 h × 60 = 150 min
Minutes to Seconds
seconds = minutes × 60
Example: 15 min × 60 = 900 s
Days to Hours
hours = days × 24
Example: 7 d × 24 = 168 h
Hours to Seconds
seconds = hours × 3,600
Example: 1 h × 3,600 = 3,600 s
Weeks to Days
days = weeks × 7
Example: 4 wk × 7 = 28 d
Years to Days
days = years × 365.25
Example: 5 y × 365.25 = 1,826.25 d
Common Time Conversions
| Unit | In Seconds | In Hours |
|---|---|---|
| 1 minute | 60 seconds | 0.0167 hours |
| 1 hour | 3,600 seconds | 1 hour |
| 1 day | 86,400 seconds | 24 hours |
| 1 week | 604,800 seconds | 168 hours |
| 1 month (avg) | 2,628,000 seconds | 730 hours |
| 1 year (avg) | 31,536,000 seconds | 8,760 hours |
Time Unit Reference Table
| Unit | Symbol | Equals | Common Uses |
|---|---|---|---|
| Nanosecond | ns | 0.000000001 s | Computer processors, light travel |
| Microsecond | μs | 0.000001 s | High-speed photography |
| Millisecond | ms | 0.001 s | Computer response times |
| Second | s | 1 s | Base SI unit, everyday timing |
| Minute | min | 60 s | Short durations, calls, meetings |
| Hour | h | 3,600 s | Work shifts, travel, events |
| Day | d | 86,400 s | Daily cycles, deadlines |
| Week | wk | 604,800 s | Projects, schedules |
| Month (avg) | mo | 2,628,000 s | Billing cycles, pregnancies |
| Year (avg) | y | 31,536,000 s | Age, anniversaries, finance |
Real-World Time Examples
| Activity/Event | Duration |
|---|---|
| Blink of an eye | 100-400 milliseconds |
| Human reaction time | 200-250 milliseconds |
| Average kiss | 12 seconds |
| Boiling an egg (soft) | 4-6 minutes |
| Boiling an egg (hard) | 9-12 minutes |
| Feature film | 90-180 minutes |
| Full work day | 8 hours |
| Flight: NYC to London | 7 hours |
| Human pregnancy | 40 weeks (280 days) |
| Earth orbit around Sun | 365.25 days |
Time Conversion Tips
Converting Decimal Hours
Multiply the decimal part by 60 to get minutes. Example: 2.75 hours = 2 hours + (0.75 × 60) = 2 hours 45 minutes. For seconds, multiply the remaining decimal by 60 again.
Converting Minutes to Decimal Hours
Divide minutes by 60. Example: 45 minutes ÷ 60 = 0.75 hours. Add to whole hours: 3 hours 45 minutes = 3.75 hours. Useful for payroll and time tracking.
Accounting for Leap Years
Use 365.25 days per year for average calculations. Leap years occur every 4 years, except century years not divisible by 400. 2000 was a leap year, 2100 will not be.
Month Length Variations
Months range from 28-31 days. For calculations, use 30.44 days (365.25 ÷ 12) as the average. Remember: "Thirty days hath September, April, June, and November..."
Time in Different Contexts
Nanoseconds
CPU clock cycles, light travels 30 cm
Microseconds
Network latency, high-speed sensors
Milliseconds
Screen refresh rates, human perception
Minutes/Hours
Meetings, calls, task durations
Days/Weeks
Project deadlines, sprints, deliverables
Months/Quarters
Billing cycles, financial reporting
Minutes
Cooking, commutes, TV episodes
Hours
Work shifts, movies, sleep
Days/Weeks
Vacations, habits, routines
Months
Pregnancy, leases, subscriptions
Years
Age, anniversaries, investments
Decades/Centuries
Historical periods, generations
Frequently Asked Questions
How many seconds are in a day?
One day contains exactly 86,400 seconds. Calculate: 24 hours × 60 minutes × 60 seconds = 86,400 seconds.
Why are there 60 seconds in a minute?
The Babylonians used a base-60 (sexagesimal) number system around 2000 BCE. Sixty divides evenly by 1, 2, 3, 4, 5, 6, 10, 12, 15, 20, and 30, making calculations easier without fractions.
How do I calculate time differences?
Convert both times to the same unit (usually minutes), subtract, then convert back. Example: 3:45 to 5:20 = 225 min to 320 min = 95 min = 1 hour 35 minutes.
What is Unix timestamp?
Unix time counts seconds since January 1, 1970, 00:00:00 UTC. It provides a simple way to represent dates in computing. January 1, 2025, equals approximately 1,735,689,600 seconds since the epoch.
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