# tdbjuliandate

Convert from Barycentric Dynamical Time Estimate to Julian date

## Syntax

``jdtdb = tdbjuliandate(terrestrial_time)``
``````[jdtdb,tttdb] = tdbjuliandate(terrestrial_time)``````

## Description

example

````jdtdb = tdbjuliandate(terrestrial_time)` returns an estimate of the Julian date for Barycentric Dynamical Time (TDB). These estimations are valid for the years 1980 to 2050.```
``````[jdtdb,tttdb] = tdbjuliandate(terrestrial_time)``` additionally returns an array of Julian dates for the Barycentric Dynamical Time (TDB) based on the Terrestrial Time (TT).```

## Examples

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Estimate the Julian date for the Barycentric Dynamical Time for the Terrestrial Time 2014/10/15 16:22:31.

`jdtdb = tdbjuliandate([2014,10,15,16,22,31])`
```jdtdb = 2.4569e+06```

Estimate the Julian dates for the Barycentric Dynamical Time and TT-TDB in seconds for the terrestrial time 2014/10/15 16:22:31 and 2010/7/22 1:57:17.

`[jdtdb,tttdb] = tdbjuliandate([2014,10,15,16,22,31;2010,7,22,1,57,17])`
```JDTDB = 1.0e+06 * 2.4569 2.4554 TTTTDB = 0.0016 0.0005```

## Input Arguments

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Terrestrial Time (TT) in year, month, day, hour, minutes, and seconds for which the function calculates the Julian date for Barycentric Dynamical Time. M is the number of Julian dates, one for each TT date. Specify values for year, month, day, hour, and minutes as whole numbers.

## Output Arguments

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Julian date for the Barycentric Dynamical Time, returned as an M-by-1 array. M is the number of rows, one for each Terrestrial Time input.

Difference in seconds between Terrestrial Time and Barycentric Dynamical Time (TT-TDB), returned as an M-by-1 array. M is the number of rows, one for each Terrestrial Time input.

## Limitations

Fundamentals of Astrodynamics and Applications[1] indicates an accuracy of 50 microseconds, which this function cannot achieve due to numerical issues with the values involved.

## References

[1] Vallado, D. A., Fundamentals of Astrodynamics and Applications, New York: McGraw-Hill, 1997.

## Version History

Introduced in R2015a