How can I instruct Splunk to ignore the time fields in a JSON string

[abassili]

I have an input that has a JSON format:

{
"a" : 0,
"b" : 0,
"time" : 1418397877,
"timezone" : "-05:00"
}

Problem is that Splunk tries to interpret the "time" and "timzone" fields and I am getting the JSON string truncated (only the first 3 lines). How can I configure the "props.conf" file to ask Splunk to ignore those time fields?

[aljohnson_splun]

DATETIME_CONFIG=NONE will prevent the timestamp extractor from running.

DATETIME_CONFIG = <filename relative to $SPLUNK_HOME>
* Specifies which file configures the timestamp extractor, which identifies timestamps from the
  event text.
* This configuration may also be set to "NONE" to prevent the timestamp extractor from running
  or "CURRENT" to assign the current system time to each event.
  * "CURRENT" will set the time of the event to the time that the event was merged from lines, or
    worded differently, the time it passed through the aggregator processor.
  * "NONE" will leave the event time set to whatever time was selected by the input layer
    * For data sent by splunk forwarders over the splunk protocol, the input layer will be the time
      that was selected on the forwarder by its input behavior (as below).
    * For file-based inputs (monitor, batch) the time chosen will be the modification timestamp on
      the file being read.
    * For other inputs, the time chosen will be the current system time when the event is read from
      the pipe/socket/etc.
  * Both "CURRENT" and "NONE" explicitly disable the per-text timestamp identification, so
    the default event boundary detection (BREAK_ONLY_BEFORE_DATE = true) is likely to not work as
    desired.  When using these settings, use SHOULD_LINEMERGE and/or the BREAK_ONLY_* , MUST_BREAK_*
    settings to control event merging.
* Defaults to /etc/datetime.xml (for example, $SPLUNK_HOME/etc/datetime.xml).

There is also MAX_TIMESTAMP_LOOKAHEAD. You could set this to a lower value so that Splunk can only look a few characters into the event for the timestamp. You may want to look at how timestamp assignment works as well.

MAX_TIMESTAMP_LOOKAHEAD = <integer>
* Specifies how far (in characters) into an event Splunk should look for a timestamp.
* This constraint to timestamp extraction is applied from the point of the TIME_PREFIX-set location.
* For example, if TIME_PREFIX positions a location 11 characters into the event, and 
  MAX_TIMESTAMP_LOOKAHEAD is set to 10, timestamp extraction will be constrained to characters 
  11 through 20.
* If set to 0, or -1, the length constraint for timestamp recognition is
  effectively disabled.  This can have negative performance implications which
  scale with the length of input lines (or with event size when LINE_BREAKER
  is redefined for event splitting).
* Defaults to 150 (characters).