# Several date math questions

**URL:** <https://discuss.elastic.co/t/several-date-math-questions/27453>\
**Category:** Elasticsearch\
**Created:** [August 16, 2015, 3:16pm UTC](https://discuss.elastic.co/t/several-date-math-questions/27453 "2015-08-16T15:16:42Z")\
**Posts on this page:** 1\
**Showing post:** 5

<div class="post-metadata">

**Author:** ![colings86](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/colings86/32/44960_2.png) [@colings86](https://discuss.elastic.co/u/colings86)\
**Post date:** [September 7, 2015, 8:56am UTC](https://discuss.elastic.co/t/several-date-math-questions/27453/5 "2015-09-07T08:56:35Z")

</div>

> [@GordonM](#):
>
> What is the native time zone and format that an Elasticsearch date field is converted into?

All dates are indexed as a long field with a value which is the epoch time in milliseconds, so effectively the dates are converted to UTC.

> [@GordonM](#):
>
> Is there a way to see a date or timestamp field how Elasticsearch sees it?

If you have enough memory to load the date field into the field data cache then you could use the ['field\_data fields'](https://www.elastic.co/guide/en/elasticsearch/reference/current/search-request-fielddata-fields.html) feature to see the indexed value, but I would only advise using that as a debugging option here and not as your final solution.

> [@GordonM](#):
>
> I am also having problems with getting weekly data, such as last week’s data, because I am not sure how to specify that that Sunday is the beginning of the week over Joda’s default Monday.
> 
> I tried this:
> 
> "range": {  
> "timestamp" : {  
> “gte”: “now/w-1d”,  
> "lt": "now"  
> }  
> }
> 
> "gte": "now/w-1d" (read as: round to the beginning of this week (Monday) and subtract one day) may generally work unless it is currently Sunday, because then a week would be Sunday to Sunday instead of Sunday to Saturday.

Would the following work instead?

```json
"range": {
   "timestamp" : {
       “gte”: “now/w-1d”,
        "lt": "(now+1w)/w - 1d"
   }
}

```

This should find the beginning of the current week for the start of the range and the beginning of the next week for the end of the range.

> [@GordonM](#):
>
> Is something similar available for simple bool range queries?

As far as I know there isn't an offset for `range` queries since you have complete control over the start and end of the range. In the `date_histogram` aggregation the `offset` parameter is used to adjust where the buckets start from but this doesn't really apply when using a single filter.

> [@GordonM](#):
>
> Alternatively, is there a setting (global or otherwise) that I can adjust to make the start of a week treated in the standard US locale way?

I don't think there is, sorry.

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