How to get Splunk to recognize correct event timestamp from extracted log?

[newbiesplunk]

Hi,
When i inject app server logs with sourcetype=access_combined, the timing for the event timestamp seems to be incorrect. The date timestamp is correct but the timing timestamp, it tag the timing as stated in the info after the GET statement.

Extracted info from the logs:
xxxxx - 1234 [07/Aug/2014:07:15:01 _0800] "Get xxxxx/20140807141314...." 200 123 ....

AT splunk, the event timestamp is:
8/7/14
14:13:14 PM xxxxx - 1234 [07/Aug/2014:07:15:01 _0800] "Get xxxxx/20140807141314...." 200 123 ....

Would like to check how to ensure the event timestamp is the timestamp as stated in the square bracket instead of the timing found in the GET statement? What had configured for this incorrect timestamp?
thks

[strive]

I think you need to override the default options of [access_combined]

Try this

Add the below stanza to your /local/props.conf

[access_combined]  
MAX_TIMESTAMP_LOOKAHEAD = 50  
TIME_PREFIX = \[  
TIME_FORMAT = %d/%b/%Y:%H:%M:%S %z