Why Elasticsearch query edit time zone

Elastic Stack Elasticsearch
1

Hi, I'm running Elasticsearch 2.3.1 CentOS release 6.7 (Final). I'm here use +8 time zone .

question:
Why save when using local time zone (+ 8), query according to time format string data is 0 time zone, but also automatically compensate time difference (query range cheap eight hours)

last is query and result.

thanks man!

  1. query
    {
    "query": {
    "bool": {
    "must": [
    {
    "range": {
    "starttime": {
    "gt": "2015-12-01 00:00:00",
    "lt": "2015-12-01 03:59:59"
    }
    }
    }
    ],
    "must_not": ,
    "should":
    }
    },
    "from": 0,
    "size": 10,
    "sort": ,
    "aggs": { }
    }

  2. result
    1448940867000
    1448942308000
    1448931935000
    1448941252000
    1448939838000
    1448935642000

  3. question
    {
    "query": {
    "bool": {
    "must": [
    {
    "range": {
    "starttime": {
    "gt": "2015-12-01 00:00:00",
    "lt": "2015-12-01 03:59:59",
    "time_zone": "+08:00"
    }
    }
    }
    ],
    "must_not": ,
    "should":
    }
    },
    "from": 0,
    "size": 10,
    "sort": ,
    "aggs": {}
    }

2.result {
"took": 3,
"timed_out": false,
"_shards": {
"total": 5,
"successful": 5,
"failed": 0
},
"hits": {
"total": 5,
....(sorry result data is long long long )

1448910912000
1448911531000
1448906069000
1448902504000
1448911803000