# Date-time of the min and max values measured using aggregateWindow

**URL:** <https://community.influxdata.com/t/date-time-of-the-min-and-max-values-measured-using-aggregatewindow/56774>\
**Category:** Systems\
**Created:** [March 17, 2025, 4:58pm UTC](https://community.influxdata.com/t/date-time-of-the-min-and-max-values-measured-using-aggregatewindow/56774 "2025-03-17T16:58:01Z")\
**Posts on this page:** 8\
**Page:** 1

<div class="post-metadata">

**Author:** ![m0hammed](https://avatars.discourse-cdn.com/v4/letter/m/3ec8ea/32.png) [@m0hammed](https://community.influxdata.com/u/m0hammed)\
**Post date:** [March 17, 2025, 4:58pm UTC](https://community.influxdata.com/t/date-time-of-the-min-and-max-values-measured-using-aggregatewindow/56774/1 "2025-03-17T16:58:01Z")

</div>

## I have this simple raw data:

| timestamp | field1 | field2 | tags |
| --- | --- | --- | --- |
| 2025-02-20T06:20:00Z | 10.0 | 40.0 | “tag1”: “v100” |
| 2025-02-20T06:24:00Z | 20.0 | 30.0 | “tag1”: “v100” |
| 2025-02-20T06:28:00Z | 30.0 | 20.0 | “tag1”: “v100” |
| 2025-02-20T06:32:00Z | 40.0 | 10.0 | “tag1”: “v100” |

My question is:  
How can I get the exact date-time of the min and max values measured using aggregateWindow?

## The desired output:

| field | function | time | value |
| --- | --- | --- | --- |
| field1 | min | 2025-02-20T06:20:00Z | 10.0 |
| field1 | max | 2025-02-20T06:32:00Z | 40.0 |
| field2 | min | 2025-02-20T06:32:00Z | 10.0 |
| field2 | max | 2025-02-20T06:20:00Z | 40.0 |

This is my flux script: for just getting the max. Once I get the associated timestamp then I will union the min and max.

from(bucket:“bucket001”)  
|\> range(start:2020-03-17T00:00:00.000000000Z, stop:2025-03-18T00:00:00.000000000Z)  
|\> filter(fn: (r) =\> (r[“\_measurement”] == “main” and r[“id”] == “32373957-4186-4374-a925-c0911cf193f6”))  
|\> sort()  
|\> aggregateWindow(every:1h, fn:max, timeSrc:“\_start”, createEmpty:false)  
|\> toFloat()  
|\> group()

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<div class="post-metadata">

**Author:** ![Anaisdg](https://sea1.discourse-cdn.com/flex023/user_avatar/community.influxdata.com/anaisdg/32/6401_2.png) [@Anaisdg](https://community.influxdata.com/u/Anaisdg)\
**Post date:** [March 18, 2025, 10:50pm UTC](https://community.influxdata.com/t/date-time-of-the-min-and-max-values-measured-using-aggregatewindow/56774/2 "2025-03-18T22:50:41Z")

</div>

Hello @m0hammed,  
Here ya go

```auto
import "array"

data = array.from(
    rows: [
        {_time: 2025-02-20T06:20:00Z, _field: "field1", _value: 10.0, tag1: "v100"},
        {_time: 2025-02-20T06:20:00Z, _field: "field2", _value: 40.0, tag1: "v100"},
        {_time: 2025-02-20T06:24:00Z, _field: "field1", _value: 20.0, tag1: "v100"},
        {_time: 2025-02-20T06:24:00Z, _field: "field2", _value: 30.0, tag1: "v100"},
        {_time: 2025-02-20T06:28:00Z, _field: "field1", _value: 30.0, tag1: "v100"},
        {_time: 2025-02-20T06:28:00Z, _field: "field2", _value: 20.0, tag1: "v100"},
        {_time: 2025-02-20T06:32:00Z, _field: "field1", _value: 40.0, tag1: "v100"},
        {_time: 2025-02-20T06:32:00Z, _field: "field2", _value: 10.0, tag1: "v100"}
    ]
)
|> range(start: 2025-02-20T06:20:00Z, stop: 2025-02-20T06:33:00Z)
|> group(columns: ["_field"]) // Ensure aggregation happens per field

min = data
  |> min() 
  |> map(fn: (r) => ({_field: r._field, function: "min", time: r._time, value: r._value}))
  |> yield(name: "min")

max = data
  |> max()
  |> map(fn: (r) => ({_field: r._field, function: "max", time: r._time, value: r._value}))
  |> yield(name: "max")

```

ofc you can replace wtih agg window just know that the `aggregateWindow()` function in Flux creates time-based windows of data and applies an aggregate function to each window. By default, window boundaries are aligned with UTC time (00:00:00), but you can control this alignment in several ways.

To align with start do something like

```auto
from(bucket: "example-bucket")
  |> range(start: -1h)
  |> filter(fn: (r) => r._measurement == "cpu" and r._field == "usage_system")
  |> aggregateWindow(every: 5m, fn: mean, offset: duration(v: int(v: v.timeRangeStart) % int(v: 5m)))
The offset calculation takes the modulus of your range start time with the window duration, effectively aligning the windows with your range start.

```

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<div class="post-metadata">

**Author:** ![m0hammed](https://avatars.discourse-cdn.com/v4/letter/m/3ec8ea/32.png) [@m0hammed](https://community.influxdata.com/u/m0hammed)\
**Post date:** [March 19, 2025, 3:42pm UTC](https://community.influxdata.com/t/date-time-of-the-min-and-max-values-measured-using-aggregatewindow/56774/3 "2025-03-19T15:42:35Z")

</div>

I’m not sure how this solve this case to get date-time of the data point. as you mentioned, there is a reason for using aggregateWindow function. I just simplified the script to describe my needs. I still need the start and stop times of the window as well as the date-time of the min/max data point, given a historical data of X years and the users want to aggregate per year, month, day, … intervals.

---

<div class="post-metadata">

**Author:** ![Anaisdg](https://sea1.discourse-cdn.com/flex023/user_avatar/community.influxdata.com/anaisdg/32/6401_2.png) [@Anaisdg](https://community.influxdata.com/u/Anaisdg)\
**Post date:** [March 20, 2025, 6:42pm UTC](https://community.influxdata.com/t/date-time-of-the-min-and-max-values-measured-using-aggregatewindow/56774/4 "2025-03-20T18:42:37Z")

</div>

Does the script I gave you above with aggregate window not work? How does it differ from your expected output?

---

<div class="post-metadata">

**Author:** ![grant1](https://sea1.discourse-cdn.com/flex023/user_avatar/community.influxdata.com/grant1/32/15107_2.png) [@grant1](https://community.influxdata.com/u/grant1)\
**Post date:** [March 21, 2025, 2:00am UTC](https://community.influxdata.com/t/date-time-of-the-min-and-max-values-measured-using-aggregatewindow/56774/5 "2025-03-21T02:00:15Z")

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Hi @m0hammed

Check out this dashboard that I created: [https://play.grafana.org/d/e7bad3ef-db0c-4bbd-8245-b85c0b2ca2b9/389d020a-e36b-58aa-a626-3b37e03730bd?orgId=1&from=now-30d&to=now&timezone=browser&var-region=$\_\_all&var-type=Demand&var-fueltype=$\_\_all&refresh=1m&editPanel=7](https://play.grafana.org/d/e7bad3ef-db0c-4bbd-8245-b85c0b2ca2b9/389d020a-e36b-58aa-a626-3b37e03730bd?orgId=1&from=now-30d&to=now&timezone=browser&var-region=$ __all&var-type=Demand&var-fueltype=$__ all&refresh=1m&editPanel=7)

It displays the Date & Time of the max value. As you change the Time Picker (last 30 days, last 2 years, last 5 years, etc.) you will get different values the table. Maybe it will give you some ideas.

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<div class="post-metadata">

**Author:** ![m0hammed](https://avatars.discourse-cdn.com/v4/letter/m/3ec8ea/32.png) [@m0hammed](https://community.influxdata.com/u/m0hammed)\
**Post date:** [March 21, 2025, 2:00pm UTC](https://community.influxdata.com/t/date-time-of-the-min-and-max-values-measured-using-aggregatewindow/56774/6 "2025-03-21T14:00:59Z")

</div>

I didn’t look at it in details but your script won’t work. You change the aggregation function mean while I’m asking for min/max and per the documentation, the offset is a “Duration to shift the window boundaries..” while I’m looking the exact timestamp of the data point.

The script I provide doesn’t work either that’s why I’m here to ask for help. I need the start and stop timestamps of the window as well as the timestamp of the min/max data point.

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<div class="post-metadata">

**Author:** ![m0hammed](https://avatars.discourse-cdn.com/v4/letter/m/3ec8ea/32.png) [@m0hammed](https://community.influxdata.com/u/m0hammed)\
**Post date:** [March 21, 2025, 2:03pm UTC](https://community.influxdata.com/t/date-time-of-the-min-and-max-values-measured-using-aggregatewindow/56774/7 "2025-03-21T14:03:05Z")

</div>

This won’t give the exact data point timestamp. My understanding is that your script is downsampling then the max function will get one of the time boundaries as timestamp. I could be wrong though.

My need is, while downsampling, I want the window timestamps boundaries as well as the data point’s timestamp.

I don’t think this is possible using Flux. There is a work around but it will require a major change to our code base.

Thanks everyone for all your suggestions!

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<div class="post-metadata">

**Author:** ![Anaisdg](https://sea1.discourse-cdn.com/flex023/user_avatar/community.influxdata.com/anaisdg/32/6401_2.png) [@Anaisdg](https://community.influxdata.com/u/Anaisdg)\
**Post date:** [April 4, 2025, 6:44pm UTC](https://community.influxdata.com/t/date-time-of-the-min-and-max-values-measured-using-aggregatewindow/56774/8 "2025-04-04T18:44:04Z")

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Hello @m0hammed,  
I provided the general logic, you can supplement aggwindow for min or max. Agg window will always give you the timestamps of the windows created by it.  
You can use window() funciton first to window your data which will create tables/groups based off of that. Then you can apply min and max functions within those windows.