Keywords: manual

# datetime.sty v2.55: Formatting Current Date and Time

Nicola L. C. Talbot
School of Computing Sciences
University of East Anglia
Norwich. NR4 7TJ.
United Kingdom.
`http://theoval.cmp.uea.ac.uk/~nlct/`

20 Aug 2007

## Contents

- Introduction
- Date Declarations
- Time Commands
- Formating Dates
- Defining New Date Formats
- Saving Dates
- Predefined Names
- Package Options
- Multilingual Support
- Configuration File
- LaTeX2HTML styles
- Troubleshooting

# Introduction

The `datetime` package is a LaTeX2e package that provides various different formats for `\today`, and provides commands for displaying the current time. If you only want the time commands but not the date changing commands, you can pass the option `nodate` to the package.

Since version 2.4, the `datetime` package has been separated into two packages: `datetime` and `fmtcount`. When I originally created this package, I defined the commands, `\ordinal` etc which could be used in the definition of `\today`. Since then, I have extended the number of commands available that can be used to display the value of a LaTeX counter, however it seems more appropriate to define all these counter-related commands in a separate package. The `fmtcount` package is now distributed separately from the `datetime` package, and will also need to be installed.

As from version 2.42, the `datetime` package is now compatible with `babel`, however you must load the `datetime` package after the `babel` package. For example:

    \usepackage[francais]{babel}
    \usepackage{datetime}

# Date Declarations

There are various declarations that change the effect of `\today`. The change can be localised by placing the declaration within a group.

Day Month Year formats:
The declaration `\longdate` will redefine `\today` to produce the current date displayed in the form Wednesday 8th March, 2000 if the package option `dayofweek` is used, or 8th March, 2000 if the package option `nodayofweek` is used.
The declaration `\shortdate` will redefine `\today` to produce the current date displayed in the form Wed 8th Mar, 2000 if the package option `dayofweek` is used, or 8th Mar, 2000 if the package option `nodayofweek` is used.
The declaration `\ddmmyyyydate` will redefine `\today` to produce the current date displayed in the form 08/03/2000
The declaration `\dmyyyydate` will redefine `\today` to produce the current date displayed in the form 8/3/2000
The declaration `\ddmmyydate` will redefine `\today` to produce the current date displayed in the form 08/03/00
The declaration `\dmyydate` will redefine `\today` to produce the current date displayed in the form 8/3/00
The declaration `\textdate` will redefine `\today` to produce the current date displayed in the form: Wednesday the Eighth of March, Two Thousand if the package option `dayofweek` is used, or Eighth of March, Two Thousand if the package option `nodayofweek` is used. Note that `\textdate` is defined for use with English, it won't look right if it is used when another language has been selected1. If you want to define a similar command for another language, you will first need to check that the `fmtcount` package supports that language.

Month Day Year formats:
The declaration `\usdate` will redefine `\today` to produce the current date displayed in the form March 8, 2000. (As TeX and LaTeX do by default.)
The declaration `\mmddyyyydate` will redefine `\today` to produce the current date displayed in the form 03/08/2000
The declaration `\mdyyyydate` will redefine `\today` to produce the current date displayed in the form 3/8/2000
The declaration `\mmddyydate` will redefine `\today` to produce the current date displayed in the form 03/08/00
The declaration `\mdyydate` will redefine `\today` to produce the current date displayed in the form 3/8/00

In addition, the declarations `\date`lang are available for all languages defined either by calling `babel` prior to `datetime` or by passing the language name as an option to `datetime`. See later if you want to define your own customised date format.

As from version 2.43, the numerical date formats (such as `\ddmmyyyydate`) use the command `\dateseparator` to separate the numbers. So, for example, if you want to hyphens instead of slashes, you can do:

    \renewcommand{\dateseparator}{-}

# Time Commands

The current time is displayed using the command `\currenttime`. The format can be changed using the declaration `\settimeformat{`style`}`, where style is the name of the format2. Available formats are:

xxivtime
  Twenty-four hour time in the form 22:28 (Default)
ampmtime
  Twelve hour time in the form 10:28pm
oclock
  Displays the current time as a string, e.g. Twenty-Eight minutes past Ten in the afternoon.

New time formats can be defined using the command:
`\newtimeformat{`name`}{`format`}`
where name is the name of the new format (used in `\settimeformat`), and format is how to format the time. Within format you can use the counters `HOUR` (number of hours after midnight), `MINUTE` (number of minutes past the hour), `HOURXII` (number of hours after midnight/midday), `TOHOUR` (the next hour) and `TOMINUTE` (number of minutes to the next hour), and the corresponding commands: `\THEHOUR`, `\THEMINUTE`, `\THEHOURXII`, `\THETOHOUR` and `\THETOMINUTE`.

For example, to define a new time format that uses a dot instead of a colon:

    \newtimeformat{dottime}{\twodigit{\THEHOUR}.\twodigit{\THEMINUTE}}

You then need to switch to this new format before you can use it:

    \settimeformat{dottime}
    \currenttime

As from version 2.43, if you only want to change the separator, you can simply redefine `\timeseparator` instead of defining a new time format. For example:

    \renewcommand{\timeseparator}{.}

The `xxivtime` format will now work like the `dottime` format defined above.

# Formating Dates

The command `\pdfdate`3 prints the date in the format required for PDF files, e.g. if the date is 1 May 2004 and time is 22:02, `\pdfdate` will print 20040501220200. The reason this date format is separate from all the others is because the other form doesn't get properly expanded by PDFTeX. (This command is defined regardless of whether the package option `nodate` is called.) Example:

    \pdfinfo{
       /Author (Me)
       /Title (A Sample Document)
       /CreationDate (D:20040501215500)
       /ModDate (D:\pdfdate)
    }

There are two commands that print the name of the current month: `\monthname` prints the current month name in full, e.g. August, and `\shortmonthname` prints the abbreviated month name, e.g. Aug. Both `\monthname` and `\shortmonthname` take an optional argument (a number from 1 to 12) if the name of a specific month is required. For example, `\monthname[6]` will produced the output: June.

The day of the week is computed using the algorithm documented at `http://userpages.wittenburg.edu/bshelburne/Comp150/DayOfWeek.htm`. This algorithm works for any date between 1st Jan, 1901 and 31st Dec, 2099. The following macros display the day of week for a given date:

`\dayofweekname{`day`}{`month`}{`year`}` prints the day of week for the specified date. For example, `\dayofweekname{31}{10}{2002}` will produce the output: Thursday.
`\shortdayofweekname`day`{`month`}{`year`}` prints the abbreviated name for the day of week for the specified date. For example
`\shortdayofweekname{31}{10}{2002}`
will produce the output: Thu.

The TeX conditional `\ifshowdow` can be used to determine whether or not the option `dayofweek` has been passed to the package. For example:

    \ifshowdow\dayofweekname{31}{10}{2002} \fi

will only display the day of week if the `dayofweek` option was passed to `datetime`. Alternatively, you can use David Carlisle's `ifthen` package:

    \ifthenelse{\boolean{showdow}}{\dayofweekname{31}{10}{2002} }{}

The command `\ordinaldate{`number`}` displays number as a date-type ordinal. If the current language is English, this will simply pass the argument to `\ordinalnum` (defined in the `fmtcount` package), if the current language is Breton, Welsh or French, a superscript will only be added if number is 1, otherwise only number will be displayed.

The macro `\formatdate{`day`}{`month`}{`year`}`4 formats the specified date according to the current format of `\today`5. (Arguments must all be integers.) For example, in combination with `\longdate`, the command

    \formatdate{27}{9}{2004}

will produce the output: Monday 27th September, 2004.

You can ensure that a number is displayed with at least two digits by using the command `\twodigit{`num`}`. This is of use if you want to define your own date or time formats.

#
Defining New Date Formats

New date formats can be defined using the command:
`\newdateformat{`name`}{`format`}`
where name is the name of the new format, and format is how to format the date. Within the argument format you can use the commands `\THEDAY`, `\THEMONTH` and `\THEYEAR` to represent the relevant day, month and year, or you can use the counters `DAY`, `MONTH` and `YEAR` if you want to use `\ordinal` etc. Once you have defined the new date format, you can then switch to it using the declaration `\`name (i.e. the name you specified preceded by a backslash), and subsequent calls to `\today` and `\formatdate` will use your new format.

For example, suppose you want to define a new date format called, say, `mydate`, that will typeset the date in the form: 8-3-2002, then you can do:

    \newdateformat{mydate}{\THEDAY-\THEMONTH-\THEYEAR}

`\newdateformat` will then define the declaration `\mydate` which can be used to switch to your new format. In the following example, two new date formats are defined, and they are then selected to produce two different formats for the current date:

    \newdateformat{dashdate}{%
    \twodigit{\THEDAY}-\twodigit{\THEMONTH}-\THEYEAR}

    \newdateformat{usvardate}{%
    \monthname[\THEMONTH] \ordinal{DAY}, \THEYEAR}

    Dash: \dashdate\today.
    US: \usvardate\today.

If the current date is, say, 8th March, 2002, the above code will produce the following: Dash: 08-03-2002. US: March 8th, 2002.

Note that `\THEDAY` etc and `DAY` etc have no real meaning outside `\newdateformat` (this is why they are in uppercase). Incidentally, the `dashdate` format is not really necessary, as you can achieve this format using:

    \renewcommand{\dateseparator}{-}
    \ddmmyyyydate

Another note: in the above code, `\ordinal` was used to illustrate the use of the `DAY` counter. It is better to use `\ordinaldate` instead:

    \newdateformat{usvardate}{%
    \monthname[\THEMONTH] \ordinaldate{\THEDAY}, \THEYEAR}

# Saving Dates

It is possible to save a date for later use using the command: 6

`\newdate{`name`}{`day`}{`month`}{`year`}`

This date can later be displayed using the same format as that used by `\formatdate` using the command:

`\displaydate{`name`}`

Individual elements of the date can be extracted using the commands:

`\getdateday{`name`}`

`\getdatemonth{`name`}`

`\getdateyear{`name`}`

# Predefined Names

The following commands are defined by the `datetime` package:

Command Name | Default Value
--- | ---
`\dateseparator` | `/`
`\timeseparator` | `:`
`\amname` | `am`
`\pmname` | `pm`
`\amorpmname` | `\amname` if morning, otherwise `\pmname`
`\amstring` | `in the morning`
`\pmstring` | `in the afternoon`
`\amorpmstring` | `\amstring` if morning, otherwise `\pmstring`
`\halfpast` | `Half past`
`\quarterpast` | `Quarter past`
`\quarterto` | `Quarter to`
`\noon` | `Noon`
`\midnight` | `Midnight`
`\oclockstring` | `O'Clock`

# Package Options

The following options may be passed to this package:

`` | long | make `\today` produce long date
`` | short | make `\today` produce short date
`` | ddmmyyyy | make `\today` produce DD/MM/YYYY date
`` | dmyyyy | make `\today` produce D/M/YYYY date
`` | ddmmyy | make `\today` produce DD/MM/YY date
`` | dmyy | make `\today` produce D/M/YY date
`` | text | make `\today` produce text date
`` | us | make `\today` produce US style date
`` | mmddyyyy | make `\today` produce MM/DD/YYYY date
`` | mdyyyy | make `\today` produce M/D/YYYY date
`` | mmddyy | make `\today` produce MM/DD/YY date
`` | mdyy | make `\today` produce M/D/YY date
`` | raise | make ordinal st,nd,rd,th appear as superscript
`` | level | make ordinal st,nd,rd,th appear level with rest of text
`` | dayofweek | make the day of week appear for `\longdate`, `\shortdate`
`` |  | or `\textdate`
`` | nodayofweek | don't display the day of week.
`` | 24hr | make `\currenttime` produce `xxivtime` format
`` | 12hr | make `\currenttime` produce `ampmtime` format
`` | oclock | make `\currenttime` produce `oclock` format
`` | nodate | Don't redefine `\today` or define the month or day of week commands
`` |  | (useful if you only want the time commands or `\pdfdate`)

The default options are: `long`, `raise`, `dayofweek` and `24hr`.

# Multilingual Support

If you want to use the `babel` package, you must load it before you load the `datetime` package. This is because the `babel` `\date`lang commands redefine `\today`, whereas the `datetime` package redefines `\today` to use `\formatdate`, and the date formatting commands (such as `\longdate`) redefine `\formatdate` rather than `\today`. This ensures consistent formatting of the dates whether you use `\today` or `\formatdate`. Therefore, the `datetime` package has to redefine all the `\date`lang commands accordingly. Thus the multilingual date support is mostly limited to that provided by `babel`. Additional support, such as the day of week names and abbreviations, are only supplied for those languages that I know, or that other people have been able to supply for me.

The commands `\monthname` and `\shortmonthname`, will produce the month name in the current language. If you want the month name in a specific language, you can use the command `\monthname`lang. For example, `\monthnamefrench[6]` will produce the output: juin. Note that `\textdate` is formatted for English dates, and won't look right if used with another language setting. If you want a textual date, the `fmtcount` package (which is loaded by `datetime`) defines some commands which display a number or ordinal as a word, but it only has very limited multilingual support. See the `fmtcount` documentation for further details.

There is currently only limited multilingual support for `\dayofweekname` and `\shortdayofweekname` (just English, French, Portuguese, Spanish and German7). You can add support for other languages by defining the commands `\dayofweeknameid`lang and `\shortdayofweeknameid`lang. Note that these commands only take one argument which should be a number from 1 to 7 indicating the day of the week.

You can use the following as templates. Replace `english` with the name of your language (as given by `\languagename`) and replace `Sunday` etc as appropriate:

    \providecommand*{\dayofweeknameidenglish}[1]{%
    \ifcase#1\relax
    \or Sunday%
    \or Monday%
    \or Tuesday%
    \or Wednesday%
    \or Thursday%
    \or Friday%
    \or Saturday%
    \fi}

    \providecommand*{\shortdayofweeknameidenglish}[1]{%
    \ifcase#1\relax
    \or Sun%
    \or Mon%
    \or Tue%
    \or Wed%
    \or Thu%
    \or Fri%
    \or Sat%
    \fi}

If you want them added to future versions of `datetime`, please email me the code.

# Configuration File

As from Version 2.4, the `datetime` package will read in settings from the configuration file `datetime.cfg`, if it exists, which will override the default package options. For example, suppose you prefer a short date without the day of week by default, you will need to create a file called `datetime.cfg` that contains the line:

    \shortdate\showdowfalse

The file `datetime.cfg` should then go somewhere on the TeX path. Now all you need to do is:

    \usepackage{datetime}

without having to specify the `short` and `nodayofweek` options.

You can also use this file to define and set your own date styles. For example, you could create a configuration file that has the following lines:

    \newdateformat{dashdate}{\twodigit{\THEDAY}-\twodigit{\THEMONTH}-\THEYEAR}
    \dashdate

Whenever you use the `datetime` package, it will now use this format by default.

# LaTeX2HTML styles

Version 2.43 and above of the `datetime` bundle supplies the LaTeX2HTML style file `datetime.perl`. This file should be placed in a directory searched by LaTeX2HTML. The following limitations apply to the LaTeX2HTML styles:

- The configuration file `datetime.cfg` is currently ignored. (This is because I can't work out the correct code to do this. If you know how to do this, please let me know.) You can however do:

      \usepackage{datetime}
      \html{\input{datetime.cfg}}

  This, I agree, is an unpleasant cludge.

- The commands `\monthname`language are not implemented.

- Some of the languages are not implemented.

- The package option `nodate` is not implemented.

# Troubleshooting

There is a `datetime` FAQ available at: `http://theoval.cmp.uea.ac.uk/~nlct/latex/packages/faq/`

#### Footnotes

... selected1
  in fact, you may get an error from the `fmtcount` package if you are using a language that it doesn't support.
... format2
  Note that the commands `\xxivtime`, `\ampmtime` and `\oclock` are still available, `\settimeformat` redefines `\currenttime` to the command given by placing a backslash in front of style. So `\settimeformat{xxivtime}` sets `\currenttime` to `\xxivtime` and so on.
... `\pdfdate`3
  thanks to Ulrich Dirr for asking about this
...year4
  Note the name change since version 1.1. The command name was changed from `\thedate` to `\formatdate` to avoid a name clash when using the `seminar` class file.
...today5
  To be more precise, `\today` is defined to be `\formatdate{`\day`}{`\month`}{`\year`}` where `\longdate` etc change the definition of `\formatdate`
... command:6
  Thanks to Denis Bitouzé for asking about this
... German7
  thanks to Uwe Bieling for supplying the German names