Specify time zones of timestamps

Specify time zones of timestamps

If you're indexing data from different time zones, you can use time zone offsets to ensure that they're correctly correlated when you search. You can configure time zones based on the host, source, or source type of an event.

Configure time zones in props.conf. For general information on editing props.conf for timestamps, see "Configure timestamp recognition".

How Splunk applies time zones

By default, Splunk applies time zones using these rules, in this order:

1. Splunk uses any time zone specified in raw event data (for example, PST, -0800).

2. Splunk uses the value of a TZ attribute set in props.conf, if the event matches the host, source, or source type specified by the stanza.

3. Splunk uses the time zone of the Splunk server that indexes the event.

Note: If you change the time zone setting in the system Splunk is running on, you must restart Splunk for it to pick up the change.

Specify time zones in props.conf

To configure time zone settings, edit props.conf in $SPLUNK_HOME/etc/system/local/ or in your own custom application directory in $SPLUNK_HOME/etc/apps/. For information on configuration files in general, see "About configuration files" in the Admin manual.

Configure time zones by adding a TZ attribute to the appropriate stanza in props.conf. The Splunk TZ attribute recognizes zoneinfo TZ IDs. (See all the time zone TZ IDs in the zoneinfo (TZ) database.) Inside the stanza for a host, source, or source type, set the TZ attribute to the TZ ID for the desired time zone. This should be the time zone of the events coming from that host, source, or sourcetype.

Note that the time zone of the indexer is not configured in Splunk, but in the underlying operating system. As long as the time is set correctly on the host system of the indexer, the offsets to event time zones will be calculated correctly.

Examples

Events are coming to this indexer from New York City (in the US/Eastern time zone) and Mountain View, California (US/Pacific). To correctly handle the timestamps for these two sets of events, the props.conf for the indexer needs the time zone to be specified as US/Eastern and US/Pacific respectively.

The first example sets the time zone to US/Eastern for any events coming from hosts whose names match the regex nyc.*:

[host::nyc*]
TZ = US/Eastern

The second example sets the time zone to US/Pacific for any events coming from sources in the path /mnt/ca/...:

[source::/mnt/ca/...]
TZ = US/Pacific

zoneinfo (TZ) database

The zoneinfo database is a publicly maintained database of time zone values.

• UNIX versions of Splunk rely on a TZ database included with the UNIX distribution you're running on. Most UNIX distributions store the database in the directory: /usr/share/zoneinfo.
• Solaris versions of Splunk store TZ information in this directory: /usr/share/lib/zoneinfo.
• Windows versions of Splunk ship with a copy of the TZ database.

Refer to the zoneinfo (TZ) database for all permissible TZ values.

Map timezone strings extracted from event data

Use the TZ_ALIAS attribute in props.conf to change Splunk's interpretation of a timezone acronym string occurring in event data. For example, "EST" means Eastern (US) Standard Time by default, but your event data might be using that value instead to designate Eastern (Australian) Standard Time. To change the meaning of "EST" to the latter, set the attribute like this:

TZ_ALIAS = EST=GMT+10:00

Then, when Splunk encounters "EST" in event data, it will interpret it as "GMT+10:00", rather than the default of "GMT- 5:00".

As this example shows, you can map a timezone string to an existing string plus offset value. You can also just map one TZ string directly to another.

When mapping timezone strings, be sure to handle both summer and winter versions of the time zones. If mapping EST, also map EDT, for example - depending on whatever your local pairs are. Test your software to see what timezone strings it produces.

You can specify multiple mappings. The syntax for TZ_ALIAS is:

TZ_ALIAS = <key=value>[,<key=value>]...

For more information, including examples, see the props.conf specification and example file in the Configuration File Reference.

Set the time zone for a user's search results

When you add or edit users using Splunk's built-in authentication, you can set a user time zone. Search results for that user will appear in the specified time zone. This setting, however, does not change the actual event data, whose time zone is determined at index time. For information on setting this value, see "Configure users with Splunk Web" in Securing Splunk.

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