Sets the DSTAMP, TSTAMP, and TODAY properties in the current project. By default, the DSTAMP property is in the format yyyyMMdd, TSTAMP is in the format hhmm, and TODAY is in the format MMMM dd yyyy. Use the nested <format> element to specify a different format.

These properties can be used in the build file, for instance, to create timestamped filenames, or used to replace placeholder tags inside documents to indicate, for example, the release date. The best place for this task is probably in an initialization target.

Since Ant 1.10.2 the magic property ant.tstamp.now can be used to specify a fixed date value in order to create reproducible builds. Its value must be a number and is interpreted as seconds since the epoch (midnight 1970-01-01). With ant.tstamp.now.iso you could also specify that value in ISO-8601 format (1972-04-17T08:07:00Z). If you specify a value in an invalid format an INFO message will be logged and the value will be ignored.

Since Ant 1.10.8 the SOURCE_DATE_EPOCH environment variable value (if set) will be honoured for reproducible builds. Ant will log a DEBUG message if an invalid value (value that cannot be parsed to an integer), is specified for that environment variable and will instead use the "current" date.


Attribute Description Required
prefix Prefix used for all properties set. No; default is no prefix

Parameters specified as nested elements

The task supports a <format> nested element that allows a property to be set to the current date and time in a given format. The date/time patterns are as defined in the Java SimpleDateFormat class. The format element also allows offsets to be applied to the time to generate different time values.

Attribute Description Required
property The property to receive the date/time string in the given pattern. Yes
pattern The date/time pattern to be used. The values are as defined by the Java SimpleDateFormat class. Yes
timezone The timezone to use for displaying time. The values are as defined by the Java TimeZone class. No
offset The numeric offset to the current time No
unit The unit of the offset to be applied to the current time. Valid values are
  • millisecond
  • second
  • minute
  • hour
  • day
  • week
  • month
  • year
locale The locale used to create date/time string. The general form is language[, country[, variant]] (either variant or both variant and country may be omitted). For more information please refer to documentation for the Locale class. No


Set the standard DSTAMP, TSTAMP, and TODAY properties according to the default formats.


Set the standard properties as well as the property TODAY_UK with the date/time pattern d-MMMM-yyyy using English locale (eg. 21-May-2001).

    <format property="TODAY_GB" pattern="d-MMMM-yyyy" locale="en,GB"/>

Create a timestamp, in the property touch.time, 5 hours before the current time. The format in this example is suitable for use with the <touch> task. The standard properties are set also.

    <format property="touch.time" pattern="MM/dd/yyyy hh:mm aa"
            offset="-5" unit="hour"/>

Set three properties with the standard formats, prefixed with start.: start.DSTAMP, start.TSTAMP, and start.TODAY.

<tstamp prefix="start"/>