# Aggregation using part of a timestamp field
**URL:** https://discuss.elastic.co/t/aggregation-using-part-of-a-timestamp-field/307858
**Category:** Kibana
**Created:** [June 22, 2022, 9:48am UTC](https://discuss.elastic.co/t/aggregation-using-part-of-a-timestamp-field/307858 "2022-06-22T09:48:36Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@mo-ezzat](https://discuss.elastic.co/u/mo-ezzat)
#### Post date: [June 22, 2022, 9:48am UTC](https://discuss.elastic.co/t/aggregation-using-part-of-a-timestamp-field/307858/1 "2022-06-22T09:48:36Z")
Hello,
I'm trying to make an aggregation using a field in the a timestamp format as
> "dateTimeReceived" : "2022-04-04T08:35:50.5566113Z"
but I just want to use the date part, so I tried using the visualization on kibana and sat the field as following
and got that
but I wanted to use date only and exclude the time, for example group all that took place in april 12 2022 together
I tried the Date Histogram but what I got was totally wrong, for some reason all the date was converted into one
I tried different min intervals, but all the same
any help with that?
thank you
---
### Author:  [@majagrubic](https://discuss.elastic.co/u/majagrubic)
#### Post date: [June 22, 2022, 11:46am UTC](https://discuss.elastic.co/t/aggregation-using-part-of-a-timestamp-field/307858/2 "2022-06-22T11:46:06Z")
Hi, I suggest you define a runtime field that would contain just the date (or month) portion of your timestamp. You can do that by going to `Data Views`, select your desired data view, click "Add Field" and then define a script for the new field value.
Eg. to get the month, you would write something like this:
`emit(doc['dateTimeReceived'].value.getMonthValue());`
Then you can use this field in aggregations as a regular field.
---
### Author:  [@mo-ezzat](https://discuss.elastic.co/u/mo-ezzat)
#### Post date: [June 22, 2022, 3:40pm UTC](https://discuss.elastic.co/t/aggregation-using-part-of-a-timestamp-field/307858/3 "2022-06-22T15:40:33Z")
Thanks for your answer, I tried what you proposed and it worked fine
I found value.toLocalDate() to get the entire date, but am having hard time finding a type for it
```auto
"runtime_mappings": {
"dateReceived": {
"type": ???,
"script": {
"source": "emit(doc['dateTimeReceived'].value.toLocalDate());"
}
```
I've tried keyword, but it isn't acceptable, any idea about that?
> "class\_cast\_exception: Cannot cast java.time.LocalDate to java.lang.String"
thank you
---
### Author:  [@majagrubic](https://discuss.elastic.co/u/majagrubic)
#### Post date: [June 23, 2022, 7:37am UTC](https://discuss.elastic.co/t/aggregation-using-part-of-a-timestamp-field/307858/4 "2022-06-23T07:37:24Z")
You'll need to call `toString()` on it to make it a text field.
---
### Author:  [@mo-ezzat](https://discuss.elastic.co/u/mo-ezzat)
#### Post date: [June 23, 2022, 7:53am UTC](https://discuss.elastic.co/t/aggregation-using-part-of-a-timestamp-field/307858/5 "2022-06-23T07:53:51Z")
Thanks a lot, that did it
have a great day there
---
### Author:  [@system](https://discuss.elastic.co/u/system)
#### Post date: [July 21, 2022, 7:54am UTC](https://discuss.elastic.co/t/aggregation-using-part-of-a-timestamp-field/307858/6 "2022-07-21T07:54:38Z")
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