juliandate

Julian date calculator

Syntax

jd = juliandate(dateVector)

jd = juliandate(dateCharacterVector,format)

jd = juliandate(year,month,day)

dy = juliandate([year,month,day])

jd = juliandate(year,month,day,hour,minute,second)

dy = juliandate([year,month,day,hour,minute,second])

Description

jd = juliandate(dateVector) converts one or more date vectors, dateVector, to Julian date, jd.

jd = juliandate(dateCharacterVector,format) converts one or more date character vectors, dateCharacterVector, to Julian date, jd, using format format.

jd = juliandate(year,month,day) and dy = juliandate([year,month,day]) return the Julian date for corresponding elements of the year,month,day arrays.

jd = juliandate(year,month,day,hour,minute,second) and dy = juliandate([year,month,day,hour,minute,second]) return the Julian date for corresponding elements of the year,month,day,hour,minute,second arrays. Specify the six arguments as one-dimensional arrays of the same length or scalar values.

Examples

Calculate Julian Date Using Date Character Version and dd-mm-yyyy Format

Calculate Julian date for May 24, 2005 using date character version and dd-mm-yyyy format:

jd = juliandate('24-May-2005','dd-mmm-yyyy')

jd =
   2.4535e+06

Calculate Julian Date Using Year, Month, and Day Inputs

Calculate Julian date for December 19, 2006 from year, month, and day inputs:

jd = juliandate(2006,12,19)

jd =
   2.4541e+06

Calculate Julian Date from Year, Month, Day, Hour, Minute, and Second Inputs

Calculate Julian date for October 10, 2004, at 12:21:00 p.m. from year, month, day, hour, month, and second inputs:

jd = juliandate(2004,10,10,12,21,0)

jd =
  2.4533e+006

Input Arguments

dateVector — Full or partial date vector

m-by-6 matrix | m-by-3 matrix | positive double-precision number

Full or partial date vector, specified as an m-by-6 or m-by-3 matrix containing m full or partial date vectors, respectively:

• Full date vector — Contains six elements specifying the year, month, day, hour, minute, and second

• Partial date vector — Contains three elements specifying the year, month, and day

Data Types: double

dateCharacterVector — Date character vector

character array | one-dimensional cell array of character vectors

Date character vector, specified as a character array, where each row corresponds to one date, or a one-dimensional cell array of character vectors.

Data Types: char | string

format — Date format

-1 (default) | character vector | string scalar | integer

Date format, specified as a character vector, string scalar, or integer. All dates in dateCharacterVector must have the same format and use the same date format symbols as the datenum function.

juliandate does not accept formats containing the letter Q.

If the format does not contain enough information to compute a date number, then:

• Hours, minutes, and seconds default to 0.

• Days default to 1.

• Months default to January.

• Years default to the current year.

Data Types: char | string

year — Year

current year (default) | scalar | one-dimensional array

Year, specified as a scalar or one-dimensional array.

Dates with two character years are interpreted to be within 100 years of the current year.

Dependencies

Depending on the syntax, specify year, month, and day or year, month, day, hour, minute, and second as one-dimensional arrays of the same length or scalar values.

Data Types: char | string

month — Month

1 (default) | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | one-dimensional array

Month, specified as a scalar or one-dimensional array from 1 to 12.

Dependencies

Depending on the syntax, specify year, month, and day or year, month, day, hour, minute, and second as one-dimensional arrays of the same length or scalar values.

Data Types: double

day — Day

1 (default) | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | one-dimensional array

Day, specified as a scalar or one-dimensional array from 1 to 31.

Dependencies

Depending on the syntax, specify year, month, and day or year, month, day, hour, minute, and second as one-dimensional arrays of the same length or scalar values.

Data Types: double

hour — Date format

0 (default) | double, whole number, 0 to 24

Hour, specified as a scalar from 0 to 24.

Dependencies

Depending on the syntax, specify year, month, and day or year, month, day, hour, minute, and second as one-dimensional arrays of the same length or scalar values.

Data Types: double

minute — Minute

0 (default) | double, whole number, 0 to 60

Minute, specified as a double, whole number from 0 to 60.

Dependencies

Depending on the syntax, specify year, month, and day or year, month, day, hour, minute, and second as one-dimensional arrays of the same length or scalar values.

Data Types: double

second — Second

0 (default) | double, whole number, 0 to 60

Second, specified as a double, whole number from 0 to 60.

Dependencies

Depending on the syntax, specify year, month, and day or year, month, day, hour, minute, and second as one-dimensional arrays of the same length or scalar values.

Data Types: double

Output Arguments

jd — Julian date

m-by-6 column vector | m-by-3 column vector

Julian date, returned as a column vector of m Julian dates, which are the number of days and fractions since noon Universal Time on January 1, 4713 BCE.

• m-by-6 column vector — Contains six elements specifying the year, month, day, hour, minute, and second

• m-by-3 column vector — Contains three elements specifying the year, month, and day

Dependencies

The output format depends on the input format:

Input Syntax	dy Format
jd = juliandate(dateVector)	m-by-6 column vector or m-by-3 column vector of m Julian dates.
jd = juliandate(dateCharacterVector,format)	Column vector of m Julian dates, where m is the number of character vectors in dateCharacterVector.

Limitations

The calculation of Julian date does not take into account leap seconds.