Possible Value for PIN_FLD_VALID_FROM_DETAILS Field

Hi,

We are running the PCM_OP_SUBSCRIPTION_CALCULATE_VALIDITY Opcode with some value in PIN_FLD_VALID_FROM_DETAILS Field,On execution it gives the below output:

Input Flist:

0 PIN_FLD_POID           POID [0] 0.0.0.1 /account 3649704 0

0 PIN_FLD_START_T      TSTAMP [0] (1462428000) Thu May  5 00:00:00 2016

0 PIN_FLD_VALID_FROM_DETAILS    INT [0] 992260

0 PIN_FLD_VALID_TO_DETAILS    INT [0] 0

0 PIN_FLD_END_T        TSTAMP [0] (0)

Output Flist:

0 PIN_FLD_POID           POID [0] 0.0.0.1 /account 3649704 0

0 PIN_FLD_START_T      TSTAMP [0] (1483336800) Sun Jan  1 23:00:00 2017

0 PIN_FLD_END_T        TSTAMP [0] (0) <null>

We just want to know on what basis is this opcode computing Start_date in the output flist from PIN_FLD_VALID_FROM_DETAILS Field value i.e