Getting Data In

Timezone conversion function.

New Member

Is there any timezone conversion function in splunk to convert timezone in search string?

Tags (2)
0 Karma

Improving on the answer above, here is a version that DOES account for daylight savings timezones, as well as times with microseconds:

| makeresults 
| eval t=strptime("2017-01-01 14:00", "%F %H:%M"),
  from_tz="UTC",
  to_tz="Australia/Melbourne",
  from_t=strptime(strftime(t, "%c.%6N " . from_tz), "%c.%6N %Z"),
  to_t=strptime(strftime(t, "%c.%6N " . to_tz), "%c.%6N %Z"),
  offset=round((from_t-to_t)/60/60),
  converted=strftime(t + (from_t-to_t), "%c")

It can be simplified for brevity, I've just broken it into different variables to make it easier to follow. Also the offset variable is unused, but is just there so you can experiment by changing dates and timezones to see that the offset does actually change depending on whether daylight savings is applicable for the date. Note that if you put in explicit DST timezone names like 'AEDT' then it will ALWAYS be daylight savings, regardless of the date. But other timezone names (like Australia/Melbourne used in the example), which are sometimes DST and sometimes not, will change offset according to the input date. The list of timezone names appear to be the standard list from Java.

Path Finder

This is a perfect solution. I modified it slightly for my use case, which is to ensure that the user's timezone matches the timezone of the source data. So the from_tz is done this way:

from_tz=strftime(now(),"%Z")
0 Karma

Explorer

Thanks. This seems to be working great. However, only one issue of DayLight Savings. When converting from EDT to Asia/Shanghai timezone, i get offset of 12 which should be 13 depending on time of the year. any idea how to fix this issue ?

0 Karma

Path Finder

Try using America/New_York for the origin timezone. This should automatically convert between EDT and EST.

0 Karma

Esteemed Legend

I revisited this and came up with this complete question and answer:
https://answers.splunk.com/answers/590067/how-do-i-map-my-personally-tz-adjusted-time-to-ano.html#an...

Inspired by the excellent answers provided here, it is possible to convert to an arbitrary timezone provided that timezone always has a fixed UTC offset (i.e. does not support day light savings time).

eval _timezone = "AEST"
| eval _time_AEST = _time 
    - (strptime("2000-01-01 +00:00", "%F %:z") - strptime("2000-01-01 " . strftime(_time, "%:z"), "%F %Z"))
    + (strptime("2000-01-01 +00:00", "%F %:z") - strptime("2000-01-01 " . _timezone, "%F %Z"))
| eval time_in_AEST = strftime(_time_AEST, "%F %T " . _timezone)

The above works by first subtracting the UTC offset of the timezone as configured in the users preferences, then adds on the UTC offset of the timezone you configure (in this example AEST, but could be -05:30 or any valid Splunk timezone identifier). The UTC offset of the two timezones in question is calculated by using a reference date (I chose 2000-01-01 arbitrarily) and parsing it twice, first using the UTC timezone and then the queried timezone, and the difference of the two yields the timezone offset.

A couple of things to remember:

  • in the example, Splunk interprets the _time_AEST variable as seconds since epoch (1970-01-01 00:00:00 UTC), and so technically Splunk is interpreting this as a different 'real world' time -- if you attempt to print the timezone of the date, it will incorrectly report the users configured timezone. Instead, whenever printing this date always include the timezone manually and don't use the %Z timezone formats (as is done in the last line of the example).
  • I discovered that Splunk Light Version 6.4.1.2 seems to have a bug where it ignores the users timezone and always reports UTC. Using the above method will not break under such circumstances.
  • The above can easily be converted to a macro. However I have found that when passing arguments to a macro it is best to use pre-calculated fields, rather than expressions (since expressions will have their " quotes stripped when passed as arguments to a macro).
  • Splunk does not seem to support the tz database - it only seems to support timezones with a fixed offset from UTC. For example, if you live in Sydney you would usually select the "Australia/Sydney" timezone from timezone dropdowns - however this item is not available in Splunks list of timezones in the user preferences. I believe this is because Sydney adheres to Day Light Savings time. If you wish to run a query using local time of an area which is not always a fixed offset from UTC, then you will have to upload a timestamp to Splunk in local time (of course this only applies if you are in control of your input sources) and not have Splunk interpret it (i.e. use a different field other than the _time property). For our use case, we are uploading the 'real world time' using time since Epoch (assigned to the _time property), and additionally upload a timestamp field formatted as a date in local time which Splunk interpets as a string. This gives Splunk enough information to assign the correct time to the event, but also allows us to run queries against the local time where the data is sourced from.

0 Karma

Esteemed Legend

The 2 functions are strptime and strftime. Here is an example string to convert _time (which is stored as UTC) to EST within a search:

... |  eval EST_time=strptime(strftime(_time,"%m/%d/%Y %H:%M:%S EST"),"%m/%d/%Y %H:%M:%S %Z") | eval date_month=strftime(EST_time,"%m") | eval date_mday=strftime(EST_time,"%d") | eval date_hour=strftime(EST_time,"%H")| stats count by date_month,date_mday,date_hour | sort count desc

I downvoted this post because this is not correct. this query says "pretend this utc date is actually a est date" which will add 5 hours (rather than subtract). what you want is to say "given this utc date, what would it be in est time"? this is not possible to do simply in splunk.

Community Manager
Community Manager

Hi @rocketboots_services

Downvoting users' answers/comments in this forum should be reserved for suggestions that could potentially do harm to someone's environment. People are just trying to help each other out and learn. Simply commenting on @woodcock's answer would have sufficed. Please review how voting etiquette works on Splunk Answers for providing positive, constructive engagement within the community:
https://answers.splunk.com/answers/244111/proper-etiquette-and-timing-for-voting-here-on-ans.html

0 Karma

SplunkTrust
SplunkTrust

I don't know to what you are referring to, but the answer by @woodcock seems like a fine example of a potential solution to the question as asked.

0 Karma

Esteemed Legend

I don't mind a downvote when I am actually wrong but he has in no way explained that I am. I stand by my answer as-is. Thanks for double-checking @rich7177.

0 Karma

Hi @rock7177 and @woodcock, thank you for pointing out that my comment was not fully explained. Apologies for incorrectly using down vote, it will not happen again (unfortunately I can't remove the vote now - "Sorry, but you can't cancel a vote after more than 1 day").

There are two problems with the provided answer: it converts not from UTC to EST, but instead from EST to UTC (the wrong direction), and it does not take the timezone configured in the users preferences into account. An example follows.

index=* | head 1 
| eval time_in = strptime("2016-10-17 00:00:00 UTC", "%F %T %Z")
| eval time_adjusted = strptime(strftime(time_in,"%F %T EST"),"%F %T %Z")
| eval time_in_printed = strftime(time_in, "%F %T %Z")
| eval time_adjusted_printed = strftime(time_adjusted, "%F %T EST")
| table time_in_printed, time_adjusted_printed

Assuming my user preferences are set to UTC timezone, then I get the following results:

time_in_printed time_adjusted_printed
2016-10-17 00:00:00 UTC 2016-10-17 05:00:00 EST

This is incorrect. The correct answer would be 2016-10-16 19:00:00 EST, see https://savvytime.com/converter/utc-to-est/00-00. The problem is that it is replacing the timezone information (+00:00) with EST (-05:00), rather than converting it. However, if my timezone is set to +10:00 Brisbane:

time_in_printed time_adjusted_printed
2016-10-17 10:00:00 AEST    2016-10-18 01:00:00 EST

This is a different but also incorrect answer. This is because the conversion method does not account for the timezone adjustment caused by updating the user preferences to anything other than UTC.

Esteemed Legend

I revisited this and came up with this complete question and answer:
https://answers.splunk.com/answers/590067/how-do-i-map-my-personally-tz-adjusted-time-to-ano.html#an...

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