Thema Time units ﹣ Converter Year to Day

Here you can convert the Time unit Year into the unit Day and vice versa you can convert Day into Year. By clicking the "Swap units" icon, you will always obtain the desired conversion in the calculation result, i.e., yr to d or d to yr. With the following calculator you can also calculate any other Time unit.

## Info about "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.

In the time unit converter, a year is always calculated to be 365 days.

In astronomical terms, a year is defined as the duration of the Earth’s orbit around the Sun, which lasts 365.25 days on average. Due to the quarter of a day, a normal calendar year (common year) is defined as 365 days, which is replaced every four years by a leap year with 366 days.

In everyday life, the term "year" is understood to mean the period from 1st January to 31st December.

## Info about "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.

For thousands of years, the astronomical day (i.e., the time from sunrise to sunrise again) was the historical basic unit of time. The first reliable time measurements were made by the Egyptians in daylight using sundials, which they divided into 12 units according to their usual system of twelve numbers. At night, they used the position of the 12 stars to measure the time at night. It was not yet so important as days were longer in summer than in winter. Basically, the day and night were divided into twelve time periods. It was only 2,000 years ago that Greek astronomers divided the day into hours of equal length.

The day as the basis for time was not replaced by the second until the middle of the 20th century. With the use of modern quartz clocks, it was proven that the astronomical day (i.e., one revolution of the Earth) is constantly becoming somewhat slower. This confirmed the assumption that magma shifts beneath the earth's mantle and also the tides slow down the Earth's rotation. Therefore, since 1956, the second has been defined in such a way that it is measured by an atomic clock and a leap second must be added to the calendar year every 2 to 5 years. Hence, a day that is actually 86,400.003 atomic seconds long is always 86,400 seconds long, and from time to time, it has a one-off of 86,401 seconds.

## Basis for conversion Year (yr) to Day (d) and vice versa

The abbreviation for the "Time unit Year" is yr. The abbreviation for the "Time unit Day" is d.

## Formula for the conversion of Year (yr) to Day (d) and vice versa

The calculation from Year to Day shall be made using the following conversion formula:

Conversion formula Year to Day

Determine the number of Day from Year

Year × 365

## Formula for the conversion of Day (d) to Year (yr)

The calculation from Day to Year shall be made using the following conversion formula:

Conversion formula Day to Year

Determine the number of Year from Day

Day × 0.0027397260288175

## Overview table : How many Year are in Day ?

Year yr ⇒ Day d
0.01 yr  are  3.65000 d
0.02 yr  are  7.30000 d
0.03 yr  are  10.95000 d
0.04 yr  are  14.60000 d
0.05 yr  are  18.25000 d
0.06 yr  are  21.90000 d
0.07 yr  are  25.55000 d
0.08 yr  are  29.20000 d
0.09 yr  are  32.85000 d
0.10 yr  are  36.50000 d
0.20 yr  are  73 d
0.30 yr  are  109.50000 d
0.40 yr  are  146 d
0.50 yr  are  182.50000 d
0.60 yr  are  219 d
0.70 yr  are  255.50000 d
0.80 yr  are  292 d
0.90 yr  are  328.50000 d
1 yr  corresponds to  365 d
2 yr  are  730 d
3 yr  are  1 095 d
4 yr  are  1 460 d
5 yr  are  1 825 d
6 yr  are  2 190 d
7 yr  are  2 555 d
8 yr  are  2 920 d
9 yr  are  3 285 d
10 yr  are  3 650 d
20 yr  are  7 300 d
30 yr  are  10 950 d
40 yr  are  14 600 d
50 yr  are  18 250 d
60 yr  are  21 900 d
70 yr  are  25 550 d
80 yr  are  29 200 d
90 yr  are  32 850 d
100 yr  are  36 500 d
200 yr  are  73 000 d
300 yr  are  109 500 d
400 yr  are  146 000 d
500 yr  are  182 500 d
600 yr  are  219 000 d
700 yr  are  255 500 d
800 yr  are  292 000 d
900 yr  are  328 500 d
1 000 yr  are  365 000 d

## Overview table : How many Day are in Year ?

Day d ⇒ Year yr
0.01 d  are  0.00002 yr
0.02 d  are  0.00005 yr
0.03 d  are  0.00008 yr
0.04 d  are  0.00011 yr
0.05 d  are  0.00013 yr
0.06 d  are  0.00016 yr
0.07 d  are  0.00019 yr
0.08 d  are  0.00021 yr
0.09 d  are  0.00024 yr
0.10 d  are  0.00027 yr
0.20 d  are  0.00054 yr
0.30 d  are  0.00082 yr
0.40 d  are  0.00109 yr
0.50 d  are  0.00137 yr
0.60 d  are  0.00164 yr
0.70 d  are  0.00191 yr
0.80 d  are  0.00219 yr
0.90 d  are  0.00246 yr
1 d  corresponds to  0.00274 yr
2 d  are  0.00547 yr
3 d  are  0.00821 yr
4 d  are  0.01095 yr
5 d  are  0.01369 yr
6 d  are  0.01643 yr
7 d  are  0.01917 yr
8 d  are  0.02191 yr
9 d  are  0.02465 yr
10 d  are  0.02739 yr
20 d  are  0.05479 yr
30 d  are  0.08219 yr
40 d  are  0.10958 yr
50 d  are  0.13698 yr
60 d  are  0.16438 yr
70 d  are  0.19178 yr
80 d  are  0.21917 yr
90 d  are  0.24657 yr
100 d  are  0.27397 yr
200 d  are  0.54794 yr
300 d  are  0.82191 yr
400 d  are  1.09589 yr
500 d  are  1.36986 yr
600 d  are  1.64383 yr
700 d  are  1.91780 yr
800 d  are  2.19178 yr
900 d  are  2.46575 yr
1 000 d  are  2.73972 yr

## Source information

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

## Last update on May 2, 2022

The pages of the "Time units" category were last editorially reviewed by Stefan Banse on May 2, 2022. 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