Confusion in Generating datasets with months frequency

[akf1990 akf1990]

Hi Guys

I have defined a dataset as following in my coordinator.xml

<datasets>
    <dataset name="output-threshold-computation"
frequency="${coord:months(1)}"
initial-instance="${dataset_initial_instance}" timezone="${timezone}">
        <uri-template>output/${YEAR}/${MONTH}</uri-template>
        <done-flag/>
    </dataset>
</datasets>

<output-events>
        <data-out name="output-fraud-threshold-computation"
dataset="output-fraud-threshold-computation">
            <instance>${coord:current(0)}</instance>
        </data-out>
    </output-events>

for a dataset_initial_instance =2012-01-01T00:00Z
   for start date =
       2014-*02*-01T00:00Z  output-threshold-computation generated is
 output/2014/*02* -> month is *equal *to month from job start time
       2014-*09*-01T00:00Z  output-threshold-computation generated is
 output/2014/*08*
       2014-*10*-01T00:00Z  output-threshold-computation generated is
 output/2014/*09  *-> month is 1 *less *than month from job start time
       2014-*11*-01T00:00Z  output-threshold-computation generated is
 output/2014/*10 *-->month is 1 *less *than month from job start time
       2014-*12*-01T00:00Z  output-threshold-computation generated is
 output/2014/*12 *--> month is* equal* to month from job start time


I am not able to comprehend this behaviour.  Please help.

Thanks in advance