Built-ins for date, time, date-time values

date, time, datetime (when used with a date/time/date-time value)

These built-ins can be used to specify which parts of the date-like variable are in use:

  • date: Date only, no time of the day.

  • time: Only the time of the day, no date part

  • datetime: Both date and time

Ideally, you do not need to use these built-ins. Unfortunately, because of the technical limitations of the Java platform, FreeMarker sometimes can’t find out which parts of a date-like value is a date, a time or a date-time; ask the programmers which variables has this problem. If FreeMarker has to execute an operation where this information is needed – such as displaying the value as text – but it does not know which parts are in use, it will stop with error. This is when you have to use these built-ins. For example, assume openingTime is a such problematic variable:

Template
<#assign x = openingTime> <#-- no problem can occur here -->
${openingTime?time} <#-- without ?time it would fail -->
<#-- For the sake of better understanding, consider this: -->
<#assign openingTime = openingTime?time>
${openingTime} <#-- this will work now -->

These built-ins can also be used to convert date-time values to date or time. For example:

Template
Last updated: ${lastUpdated} <#-- assume that lastUpdated is a date-time value -->
Last updated date: ${lastUpdated?date}
Last updated time: ${lastUpdated?time}

will output something like:

Output
Last updated: 04/25/2003 08:00:54 PM
Last updated date: 04/25/2003
Last updated time: 08:00:54 PM

If the left side of the ? is string, then these built-ins convert strings to date/time/date-time.

date_if_unknown, time_if_unknown, datetime_if_unknown

The date_if_unknown, time_if_unknown, datetime_if_unknown built-ins mark a date-like value with some of the sub-types: date without time, time, or date-time, respectively. However, if the value already holds this information, the built-in has no effect. That is, it will never convert the sub-type of a value, it only adds the sub-type if it was unknown.

iso_…

These built-ins convert a date, time or date-time value to string that follows ISO 8601:2004 “extended” format.

This built-in has several variations: iso_utc, iso_local, iso_utc_nz, iso_local_nz, iso_utc_m, iso_utc_m_nz, etc. The name is constructed from the following words in this order, each separated with a _ from the next:

  1. iso (required)

  2. Either utc or local (required (except when it’s given with a parameter, but see that later)): Specifies whether you want to print the date/time/date-time according to UTC or according the current time zone. The current time zone is decided by the time_zone FreeMarker setting and is normally configured by the programmers outside the templates (but it can also be set in a template, like <#setting time_zone="America/New_York"> for example).

  3. Either h or m or ms (optional): The accuracy of the time part. When omitted, it defaults to seconds accuracy (like 12:30:18). h means hours accuracy (like 12), m means minutes accuracy (12:30), and ms means milliseconds accuracy (12:30:18.25, where we have 250 ms). Note that when using ms, the milliseconds are displayed as fraction seconds (following the standard) and will not have trailing 0-s. Thus, if the the millisecond part happens to be 0, the whole fraction second part will be omitted. Also note that the fraction seconds are always separated with a dot , not with comma (to follow the Web conventions and XML Schema time/dateTime canonical format).

  4. nz (optional): nz (like in ${foo?utc_local_nz}) stands for “no zone”, which means that the time zone offset (like +02:00 or -04:30 or Z) will not be displayed. If this part is omitted (like in ${foo?utc_local}) the zone will be displayed, except in case the value is a date (no time part) value (again, ISO 8901 doesn’t allow it then).

Note that the offset always contains the minutes for XML Schema date/time/dateTime format compliance. (However, if you primarily generate for the XML Schema format, use the xs format.)

Example:

Template
<#assign aDateTime = .now>
<#assign aDate = aDateTime?date>
<#assign aTime = aDateTime?time>

Basic formats:
${aDate?iso_utc}
${aTime?iso_utc}
${aDateTime?iso_utc}

Different accuracies:
${aTime?iso_utc_ms}
${aDateTime?iso_utc_m}

Local time zone:
${aDateTime?iso_local}

A possible output (depends on current time and time zone):

Output
Basic formats:
2011-05-16
21:32:13Z
2011-05-16T21:32:13Z

Different accuracies:
21:32:13.868Z
2011-05-16T21:32Z

Local time zone:
2011-05-16T23:32:13+02:00

There is yet another group of iso_... built-in variants, where you omit the local or utc word from the name and instead specify the time zone as a parameter to the built-in. Example:

Template
<#assign aDateTime = .now>
${aDateTime?iso("UTC")}
${aDateTime?iso("GMT-02:30")}
${aDateTime?iso("Europe/Rome")}

The usual variations are supported:
${aDateTime?iso_m("GMT+02")}
${aDateTime?iso_m_nz("GMT+02")}
${aDateTime?iso_nz("GMT+02")}

A possible output (depends on current time and time zone):

Output
2011-05-16T21:43:58Z
2011-05-16T19:13:58-02:30
2011-05-16T23:43:58+02:00

The usual variations are supported:
2011-05-16T23:43+02:00
2011-05-16T23:43
2011-05-16T23:43:58

If the time zone parameter can’t be interpreted, the template processing will be terminated with error.

string (when used with a date/time/date-time value)

This built-in converts a date to a string, with the specified formatting.

You should need this built-in rarely, as the default format of date/time/date-time values can be specified globally with the date_format, time_format and datetime_format settings of FreeMarker. Use this built-in only at the places where the desired format differs from the one normally used.

The desired format can be specified like ?string.format or ?string["format"]. These are equivalent, except that with the quoted formats you can include any characters in the format, like spaces. The syntax of format is exactly the same as of the date_format, time_format and datetime_format configuration settings; see the documentation of the possible values there.

Example: If the locale of the output is U.S. English, and the time zone is the U.S. Pacific Time zone, and openingTime is a time, nextDiscountDay is date and lastUpdated is datetime or date then this:

Template
<#-- Predefined format names: -->

${openingTime?string.short}
${openingTime?string.medium}
${openingTime?string.long}
${openingTime?string.full}
${openingTime?string.xs} <#-- XSD xs:time -->
${openingTime?string.iso} <#-- ISO 8601 time -->

${nextDiscountDay?string.short}
${nextDiscountDay?string.medium}
${nextDiscountDay?string.long}
${nextDiscountDay?string.full}
${nextDiscountDay?string.xs} <#-- XSD xs:date -->
${nextDiscountDay?string.iso} <#-- ISO 8601 date -->

${lastUpdated?string.short}
${lastUpdated?string.medium}
${lastUpdated?string.long}
${lastUpdated?string.full}
${lastUpdated?string.medium_short} <#-- medium date, short time -->
${lastUpdated?string.xs} <#-- XSD xs:dateTime -->
${lastUpdated?string.iso} <#-- ISO 8601 combined date and time -->

<#-- Programmer-defined named format (@ + name): -->
${lastUpdated?string.@fileDate}

<#-- Advanced ISO 8601 and XSD formatting: -->
${lastUpdated?string.iso_m_u}
${lastUpdated?string.xs_ms_nz}

<#-- SimpleDateFormat patterns: -->
${lastUpdated?string["dd.MM.yyyy, HH:mm"]}
${lastUpdated?string["EEEE, MMMM dd, yyyy, hh:mm a '('zzz')'"]}
${lastUpdated?string["EEE, MMM d, ''yy"]}
${lastUpdated?string.yyyy} <#-- Same as ${lastUpdated?string["yyyy"]} -->

will print something like this:

Output
01:45 PM
01:45:09 PM
01:45:09 PM PST
01:45:09 PM PST
13:45:09-08:00
13:45:09-08:00

2/20/07
Apr 20, 2007
April 20, 2007
Friday, April 20, 2007
2007-02-20-08:00
2007-02-20

2/20/07 01:45 PM
Feb 20, 2007 01:45:09 PM
February 20, 2007 01:45:09 PM PST
Friday, February 20, 2007 01:45:09 PM PST
Feb 8, 2003 9:24 PM
2007-02-20T13:45:09-08:00
2007-02-20T13:45:09-08:00

Apr/20/2007 13:45

2007-02-20T21:45Z
2007-02-20T13:45:09.000

08.04.2003 21:24
Tuesday, April 08, 2003, 09:24 PM (PDT)
Tue, Apr 8, '03
2003

Note that with custom formats like in lastUpdated?string.@fileDate above, templates can just refer to the application-domain meaning, and the exact format can be specified outside the templates, on a central place. (Programmers can read about defining such named formats here…)

You never need to use ?date, ?time or ?datetime with format patterns like "yyyy.MM.dd HH:mm", since with the pattern you tell FreeMarker what parts of the date to show. However, FreeMarker will trust you blindly, so you can show “noise” if you display parts that are actually not stored in the variable. For example, ${openingTime?string["yyyy-MM-dd hh:mm:ss a"]}, where openingTime stores only time, will display 1970-01-01 09:24:44 PM.

To prevent misunderstandings, the format need not be a string literal, it can be a variable or any other expression as far as it evaluates to a string. For example, it can be like "..."?string[myFormat].

See also: the interpolation of dates