<blockquote>
  <p>Is it the only difference?</p>
</blockquote>

<p>By definition, yes. It's important to keep in mind that the difference between TT and UT (UT1) is not constant.</p>

CC BY-SA 3.0
2015-08-05T06:11:37.200Z
2015-08-05T06:11:37.200Z
David Hammen
<p>I'm making a code where I calculate the sun position in a given time. But I also want to learn astronomy with it. I'm following a .pdf to make the program, and in this .pdf it says </p>

<blockquote>
  <p>The Julian Day (JD) is calculated using UT and the Julian Ephemeris
  Day (JDE) is calculated using TT.</p>
</blockquote>

<p>Is it the only difference?</p>

<time>
What's the difference between the Julian and the Julian Ephemeris Day?
Vlocks
# What's the difference between the Julian and the Julian Ephemeris Day?

(Asked by: username_0 on 2015-08-04)

I'm making a code where I calculate the sun position in a given time. But I also want to learn astronomy with it. I'm following a .pdf to make the program, and in this .pdf it says

> The Julian Day (JD) is calculated using UT and the Julian Ephemeris
> Day (JDE) is calculated using TT.

Is it the only difference?

**Tags:** time


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## 1 answers

### Answer by username_1 on 2015-08-05. Score: 0 | Accepted answer

> Is it the only difference?

By definition, yes. It's important to keep in mind that the difference between TT and UT (UT1) is not constant.


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