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Date Vector/Number to ISO 8601 Date String

version 1.17 (6.27 KB) by

Convert a Date Vector/Number to an ISO 8601 Date String. Tokens control the date/time notation.

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Easy conversion of a date vector or a serial date number into a date string. The date string may be an ISO 8601 timestamp or a single date/time value, selected by (optional) input token/s. Multiple tokens may be used to output multiple strings.

The ISO 8601 timestamp style options supported by this function are:
* Date in calendar, ordinal or week-numbering notation.
* Basic or extended format.
* Choice of date-time separator character.
* Full or lower precision (fewer trailing date/time units).
* Decimal fraction of the trailing unit (decimal places).

By default the function uses the current time and returns the basic ISO 8601 calendar timestamp: this is very useful for naming files that sort alphabetically into chronological order!

### Examples ###

Examples use the date+time described by the vector [1999,1,3,15,6,48.0568].

datestr8601
 ans = '19990103T150648'

datestr8601([],'yn_HM')
 ans = '1999003_1506'

datestr8601(clock,'*ymdHMS')
 ans = '1999-01-03T15:06:48'

[D1,D3] = datestr8601(now-2,'D','DDD')
 D1 = '5'
 D3 = 'Fri'

datestr8601(clock,'DDDD','ddd','mmmm','yyyy')
 ans = 'Sunday 3rd January 1999'

[ddd,YWD,mmyy] = datestr8601([],'ddd','*YWD','mmmm','yyyy');
sprintf('The %s of %s has the ISO week-date "%s".',ddd,mmyy,YWD)
 ans = 'The 3rd of January 1999 has the ISO week-date "1998-W53-7".'

### ISO 8601 Date Notations ###

Timestamps are shown here in extended format with the default date-time separator character 'T'.

1) Calendar:
<year>-<month>-<dayofmonth>T<hour>:<minute>:<second>
string: '1999-01-03T15:06:48'
token: '*ymdHMS'

2) Ordinal:
<year>-<dayofyear>T<hour>:<minute>:<second>
string: '1999-003T15:06:48'
token: '*ynHMS'

3) Week-numbering:
<year>-W<weeknumber>-<dayofweek>T<hour>:<minute>:<second>
string: '1998-W53-7T15:06:48'
token: '*YWDHMS'

### Single Value Strings ###

* One date/time value per output string (note: can be concatenated afterwards).
* Consistent token syntax.
* Easily adapted to other languages.
* Single Values include: day of the year or days remaining in year; year quarter (3-month or 13-week); year; month as digit or name; day of week as digit or name; date of month; hour; minute; second; deci/centi/milliseconds.

Comments and Ratings (1)

Long

Long (view profile)

Thanks a lot. A very useful subroutine.

Updates

1.17

* Update online blurb.
* Add concatenation of remaining strings into last output (if more tokens than outputs).

1.16

- Downloadable as toolbox

1.15

- Remove calendar week number (confusing!)

1.14

- Improve token input checking and error messages.
- Restrict date-time separator character to ' ','T','@','_'.
- Add ordinals for Day of Year (required token format change).

1.13

- Removed 'F' from ISO 8601 timestamps: please use decimal fraction instead.
- Complete list of date-time separator exclusions.
- Improve examples.
- Simpler Midnight/AM/Noon/PM calculation.

1.12

- Disallow period '.' as date-time separator character.

1.11

ISO 8601 dates/timestamps:
- Allow decimal fraction of any trailing unit (decimal places).
- Allow choice of any date-time separator character.

1.9

- Allow 'F' (millisecond) in 8601 timestamp tokens.

1.8

- Fix bug in Midnight/AM/Noon/PM calculation.
- More examples.

1.7

- Help improved to better contrast calendar vs week-numbering dates.
- Remove basic format prefix 'B', and add extended format prefix '*' (logical, easier to read and search for).
- Test function string can be displayed directly in command window.

1.6

- Add day-of-week (as a number) and year (week-date) tokens.
- Examples that better illustrate the ISO 8601 week date.
- Change token syntax (for consistency with calendar / week-date year-type).

1.5

Add default time (current time).
Add default token 'BymdHMS'.
Add ordinal date with suffix, eg '3rd'.

1.4

- Now accepts Date Number OR Date Vector.
- Now accepts multiple input Tokens (to provide multiple output Strings).
- Add 13-week year-quarter token.
- Improve help documentation.

1.3

Added Ordinal Date style, and format control.

1.2

Some corrections to Description field and Mfile help comments.

MATLAB Release
MATLAB 7.11 (R2010b)

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