unixtime_microseconds_todatetime

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

unixtime_microseconds_todatetime converts a Unix timestamp that is expressed in whole microseconds since 1970-01-01 00:00:00 UTC to an APL datetime value.

Use the function whenever you ingest data that stores time as epoch microseconds (for example, JSON logs from NGINX or metrics that follow the StatsD line protocol). Converting to datetime lets you bin, filter, and visualize events with the rest of your time-series data.

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, you often convert epoch values with eval ts=strftime(_time,"%Y-%m-%dT%H:%M:%S.%6N"). In APL, the conversion happens with a scalar function, so you can use it inline wherever a datetime literal is accepted.

Splunk example

| eval eventTime=strftime( micro_ts/1000000 , "%Y-%m-%dT%H:%M:%S.%6N")

ANSI SQL users

Standard SQL engines rarely expose microsecond-epoch helpers. You usually cast or divide by 1,000,000 and add an interval. APL gives you a dedicated scalar function that returns a native datetime, which then supports the full date-time syntax.

SQL example

SELECT TIMESTAMP '1970-01-01 00:00:00' + micro_ts / 1000000 * INTERVAL '1 second' FROM events;

Usage

Syntax

unixtime_microseconds_todatetime(microseconds)

Parameters

Name	Type	Description
microseconds	int or long	Whole microseconds since the Unix epoch. Fractional input is truncated.

Returns

A datetime value that represents the given epoch microseconds at UTC precision (1 microsecond).

Use case example

The HTTP access logs keep the timestamp as epoch microseconds and you want to convert the values to datetime.

Query

['sample-http-logs']
| extend epoch_microseconds = toint(datetime_diff('Microsecond', _time, datetime(1970-01-01)))
| extend datetime_standard = unixtime_microseconds_todatetime(epoch_microseconds)
| project _time, epoch_microseconds, datetime_standard

Run in Playground

Output

_time	epoch_microseconds	datetime_standard
May 15, 12:09:22	1,747,303,762	2025-05-15T10:09:22Z

This query converts the timestamp to epoch microseconds and then back to datetime for demonstration purposes.

List of related functions

• unixtime_milliseconds_todatetime: Converts a Unix timestamp expressed in whole milliseconds to an APL datetime value.
• unixtime_nanoseconds_todatetime: Converts a Unix timestamp expressed in whole nanoseconds to an APL datetime value.
• unixtime_seconds_todatetime: Converts a Unix timestamp expressed in whole seconds to an APL datetime value.