# Timestamp with aggregatewindow function
**URL:** https://community.influxdata.com/t/timestamp-with-aggregatewindow-function/33072
**Category:** Fluxlang
**Created:** [February 2, 2024, 9:01pm UTC](https://community.influxdata.com/t/timestamp-with-aggregatewindow-function/33072 "2024-02-02T21:01:57Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@user642](https://community.influxdata.com/u/user642)
#### Post date: [February 2, 2024, 9:01pm UTC](https://community.influxdata.com/t/timestamp-with-aggregatewindow-function/33072/1 "2024-02-02T21:01:57Z")
I want to have the average temperature per day. But when i use the aggregation function it sets the timestamp at the end.
I dont understand why. The average temp of a day with timestamp at 0:00 at the next day doesnt seem to make any sense to me. Wouldnt it be better to have the timestamp at 12:00 because thats the middle of the day?
how do i know where the data comes from later? In my opition i need 2 timestamps. One for the beginning and one for the end.
Or do i have later to shift my axis by -12h to have the point in grafana at the middle of the day?
---
### Author:  [@Anaisdg](https://community.influxdata.com/u/Anaisdg)
#### Post date: [February 2, 2024, 10:01pm UTC](https://community.influxdata.com/t/timestamp-with-aggregatewindow-function/33072/2 "2024-02-02T22:01:43Z")
Hello @user642 Welcome!
Deciding how to bound windows of time is always challenging in the space and there are pros and cons to each.
Some people want a window defined by the start of the day 00:00 others want 24:00 but others also don’t like 24:00 because its techinically in the next day so they really want 23:59. You want 12:00. Every use case is different. I like your idea of having bounds.
the window() funciton gives you start and stop window times
> **[window() function | Flux Documentation](https://docs.influxdata.com/flux/v0/stdlib/universe/window/#Copyright)**
>
> window() groups records using regular time intervals.
If you query your data from the start of a day and then window() youll get start and stop columns that reflect those window start and stop times.
then you can use an empty |\> group() to put all of those windows into one table if you need 🙂
I hope that helps.
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### Author:  [@Francis](https://community.influxdata.com/u/Francis)
#### Post date: [May 30, 2024, 11:30am UTC](https://community.influxdata.com/t/timestamp-with-aggregatewindow-function/33072/3 "2024-05-30T11:30:28Z")
I have the same concern as @user642, and I find that the provided link to the window() function does not answer the question. How would I go about getting the queried values to have a timestamp equal to the _start_ of the aggregate window?
For context, I’ve provided the image below that shows a chart with data at irregular intervals (dots), the _expected_ values at a fixed-interval query with interpolation between points, and the results of the query that I’ve been able to cobble together in _Flux_. The queried points are offset by 5s (the duration of the aggregate window) when compared to the expected values.
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### Author:  [@Francis](https://community.influxdata.com/u/Francis)
#### Post date: [May 31, 2024, 4:04pm UTC](https://community.influxdata.com/t/timestamp-with-aggregatewindow-function/33072/4 "2024-05-31T16:04:02Z")
To answer my own question, this is doable with the timeShift function:
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### Author:  [@scott](https://community.influxdata.com/u/scott)
#### Post date: [June 5, 2024, 3:55pm UTC](https://community.influxdata.com/t/timestamp-with-aggregatewindow-function/33072/5 "2024-06-05T15:55:11Z")
@Francis There’s a simpler answer to your problem. `aggregateWindow()` includes a `timeSrc` parameter that lets you specify the column to use for the output timestamps. By default, this is `_stop`. You can set it to `_start` to using the starting boundary of each window as the output timestamp:
```javascript
//...
|> aggregateWindow(every: 5s, fn: first, createEmpty: false, timeSrc: "_start")
```
No need to use `timeShift()` after `aggregateWindow()`.