getmonth

This page explains how to use the getmonth function in APL.

Use the getmonth function in APL to extract the month number from a datetime value. The function returns an integer from 1 to 12, where 1 represents January and 12 represents December.

You can use getmonth to group records by month when analyzing seasonal patterns, monthly trends, or periodic fluctuations in your data. This is useful for dashboards, monthly reporting, and cohort analysis.

Use it when you want to:

• Aggregate events by month for trend analysis.
• Compare metrics across months to detect seasonal patterns.
• Create monthly summaries across log, trace, or security datasets.

For users of other query languages

If you come from other query languages, this section explains how to adjust your existing queries to achieve the same results in APL.

Splunk SPL users

In Splunk SPL, you typically use the strftime function with the %m specifier to extract the month number. In APL, the getmonth function directly returns the month number as an integer.

Splunk example

... | eval month=strftime(_time, "%m")

... | extend month = getmonth(_time)

ANSI SQL users

In ANSI SQL, you use EXTRACT(MONTH FROM timestamp) or the MONTH() function to get the month number. In APL, getmonth provides the same result.

SQL example

SELECT EXTRACT(MONTH FROM timestamp_column) AS month FROM events;

['dataset']
| extend month = getmonth(_time)

Usage

Syntax

getmonth(datetime)

Parameters

Name	Type	Description
datetime	datetime	The input datetime value.

Returns

An int from 1 to 12 representing the month number.

Use case examples

Log analysis

Analyze HTTP request volume by month to identify traffic patterns throughout the year.

Query

['sample-http-logs']
| extend month = getmonth(_time)
| summarize request_count = count() by month
| sort by month asc

Run in Playground

Output

month	request_count
1	4521
2	4187
3	4893

This query groups HTTP log entries by month number and counts the requests in each month.

OpenTelemetry traces

Compare monthly average span durations by service to spot performance changes across months.

Query

['otel-demo-traces']
| extend month = getmonth(_time)
| summarize avg_duration = avg(duration) by month, ['service.name']
| sort by month asc

Run in Playground

Output

month	service.name	avg_duration
1	frontend	00:00:01.2340000
2	frontend	00:00:01.1890000
3	frontend	00:00:01.3020000

This query calculates the average span duration per month for each service, helping you track monthly performance trends.

Security logs

Find which months have the most server errors to uncover seasonal reliability patterns.

Query

['sample-http-logs']
| where toint(status) >= 500
| extend month = getmonth(_time)
| summarize error_count = count() by month
| sort by error_count desc

Run in Playground

Output

month	error_count
7	89
12	76
3	54

This query identifies the months with the highest number of server errors, sorted by error count in descending order.

List of related functions

• monthofyear: Returns the month number from a datetime. Equivalent to getmonth.
• getyear: Extracts the year part from a datetime as an integer.
• dayofmonth: Returns the day of the month from a datetime.
• startofmonth: Returns the start of the month for a datetime, useful for monthly binning.
• endofmonth: Returns the end of the month for a datetime value.