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

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 \datelang 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 \pdfdate3 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.
\shortdayofweeknameday{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 \today5. (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 \datelang 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 \datelang 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 \monthnamelang. 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 \dayofweeknameidlang and \shortdayofweeknameidlang. 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:

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.
... \pdfdate3
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


Nicola L. C. Talbot. School of Computing Sciences. University of East Anglia. Last Modified: 2007-08-20