# Time Conversion

Updated on by Stefan Banse

The time converter helps you to convert all common time units into the ones you desire. Behind the "help" buttons, you will also find a lot of interesting information about the selected time unit.

## Time Calculator

How many seconds make 1.6 minutes? How many minutes make 3.2 hours? These and similar questions often present minor difficulties. Unlike many other units, time units are not always converted into each other using the familiar decimal system as powers of ten (i.e., 10, 100, 1,000 etc.). There are 365 days in a year, 24 hours in a day, 60 minutes in an hour and 60 seconds in a minute.

This is followed by only fractions of the basic unit of time (the second), then the familiar decimal system: tenths of a second, hundredths of a second, thousandths of a second, etc.

## Operator Assistant

Enter the time unit to be converted and select from and into which time unit this value is to be converted. The time converter provides the common metric and astronomical time units for the calculation. Further information on the various time units is hidden behind the calculator's "help" buttons marked with a question mark.

## The different time units

Below you will find information on all the time units that can be converted in the time converter.

### Millennium

A millennium (abbreviated as ml) represents a period of one thousand years. A millennium consists of ten centuries. Like the year itself, the millennium is not part of the international system of units.

### Century

A century (abbreviated as c) represents a period of one hundred years. Ten centuries make up a millennium. Like the year itself, the century is not part of the international system of units.

A decade represents a period of ten years. Like the year itself, the decade is not part of the international system of units.

### Year

A year (a) (Latin: annus) forms the time span of 365 days, or in the case of a leap year, 366 consecutive days. Due to its varying length, the year is not a physical unit of time and thus not a unit of time in the international SI system of units.

### Month

A month forms the time span of 28, 29, 30 or 31 consecutive days. Due to its varying length, the month is not a physical unit of time and thus not a unit of time in the international SI system of units.

### Week

In today’s culture, the “week” is a common unit of time comprising seven days. However, it is neither a legal unit nor a physical unit of time in terms of the International System of Units(SI), compared to seconds, minutes or hours.

Here, 1 week is equivalent to 7 days, 1 day is therefore equal to 0.14286 weeks.

### Day

Although the day (d) (Latin: dies) is not part of the International SI System of Units, it is indirectly approved for use with the SI through its definition that a day has 24 hours, and it is indirectly permitted for use with the SI. This is because the second form the official SI base value.

Therefore, 1 day equals 24 hours; 1440 minutes = 86,400 seconds 1 second equals 0.0000115741 days.

### Hour

The hour (h) (Latin: hora) is not part of the International SI System of Units, but it is permitted for use with the SI. The hour is derived from the base unit second. This makes it a legal unit of measurement.

Here, 1 hour is equal to 3,600 seconds or 1 second is equal to 0.00027778 hours (3,600ths).

### Minute

The minute (min) is not part of the SI International System of Units, but it is approved for use with the SI. The minute is derived from the base unit second. This makes it a legal unit of measurement.

Therefore, 1 minute equals 60 seconds, or 1 second equals 0.0166667 minutes.

### Second

The second (s) is the base unit of time in the International System of Units (SI). Therefore, the second is the physical unit of time measurement.

All other units of time are derived from the second (e.g., 1 minute = 60 seconds, 1 second = 1,000 milliseconds).

### Tenth of a second

The unit tenth of a second or decisecond can be traced back to the basic unit second. Here, 1 tenth of a second corresponds to 0.1 seconds or 1 second corresponds to 10 tenths of a second. The prefix “deci” in the term decisecond stands for one-tenth of the base unit second.

This unit belongs to the International System of Units (SI).

### Hundredth of a second

The unit hundredths of a second or centisecond can be traced back to the basic unit second. Here, 1 hundredth of a second corresponds to 0.01 seconds or 1 second corresponds to 100 hundredths of a second. The prefix "centi" in the term centisecond stands for one-hundredth of the basic unit second.

This unit belongs to the International System of Units (SI).

### Millisecond

The unit millisecond or thousandth of a second can be traced back to the basic unit second. Here, 1 millisecond corresponds to 0.001 seconds or 1 second corresponds to 1,000 milliseconds. The prefix "milli" in the term millisecond stands for one-thousandth of the base unit second.

This unit belongs to the International System of Units (SI).

### Microsecond

The unit “microsecond” can be traced back to the basic unit second. Therefore, 1 microsecond corresponds to 0.000001 seconds or 1 second corresponds to 1,000,000 microseconds. The prefix "micro" in the term microsecond stands for one-millionth of the base unit second.

This unit belongs to the International System of Units (SI).

### Nanosecond

The unit “nanosecond” can be traced back to the basic unit second. Therefore, 1 nanosecond corresponds to 0.000000001 seconds or 1 second corresponds to 1,000,000,000 nanoseconds. The prefix "nano" in the term nanosecond stands for one-billionth of the basic unit second.

This unit belongs to the International System of Units (SI).

### Other time units

There are other numerous SI time units that represent a fraction of a second. As a result, these so-called unit prefixes (i.e., prefixes for the second) are formed, as in the previous examples.

Compared to other units such as the weight units and the base unit “gram”, this is not common in the base unit of time (i.e., the second: "kilogram"; second: "kiloseconds" or "megaseconds" tend not to be used). The reason is that, in the case of time, the multiples of the second are not based on the decimal system and thus are not usually represented as powers of 10. The multiples of the second are usually and commonly represented as follows: 60 times, 24 times, or 365 times.

The following table gives an overview of the prefix used for the fraction of a second:

Symbol Name Value
s Second 100 one second
ds Decisecond 10-1 Tenth of a second
cs Centisecond 10-2 Hundredth of a second
ms Millisecond 10-3 Thousandth of a second
µm Microsecond 10-6 Millionth of a second
ns Nanosecond 10-9 Billionth of a second
ps Picosecond 10-12 Trillionth of a second
fs Femtosecond 10-15 Quadrillionth of a second
as Attosecond 10-18 Quintillionth of a second
zs Zeptosecond 10-21 Sextillionth of a second
ys Yoctosecond 10-24 Septillionth of a second

## Source information

As source for the information in the "Time units" category, we have used in particular:

## Last update on November 4, 2021

The pages of the "Time units" category were last editorially reviewed by Stefan Banse on November 4, 2021. They all correspond to the current status.

### Previous changes on April 24, 2021

• April 24, 2021: Publication of the time units converter.
• Editorial revision of all texts in this category