Keeping relative time format w/o conversion to absolute time format

Hi all,

Is there a possibility to keep validity_period of MT which sending from
opensmppbox to external SMSCs in the relative time format unchanged? For
now, I see the kannel changing it to the absolute time format.

For example, this is a snippet from the opensmppbox logfile (this was a
submit_sm where is the vp was set to 1 minute):

2018-07-17 10:57:20 [29721] [421] DEBUG:   validity_period:
"000000000100000R"

That is a snippet from SMSC log:

2018-07-17 10:57:20 [2565] [25] DEBUG: SMPP PDU 0x7fe864004010 dump:
2018-07-17 10:57:20 [2565] [25] DEBUG:   type_name: submit_sm
2018-07-17 10:57:20 [2565] [25] DEBUG:   command_id: 4 = 0x00000004
2018-07-17 10:57:20 [2565] [25] DEBUG:   command_status: 0 = 0x00000000
2018-07-17 10:57:20 [2565] [25] DEBUG:   sequence_number: 225108 =
0x00036f54
2018-07-17 10:57:20 [2565] [25] DEBUG:   service_type: "CMT"
...
2018-07-17 10:57:20 [2565] [25] DEBUG:   esm_class: 3 = 0x00000003
2018-07-17 10:57:20 [2565] [25] DEBUG:   protocol_id: 0 = 0x00000000
2018-07-17 10:57:20 [2565] [25] DEBUG:   priority_flag: 1 = 0x00000001
2018-07-17 10:57:20 [2565] [25] DEBUG:   schedule_delivery_time: NULL
2018-07-17 10:57:20 [2565] [25] DEBUG:   validity_period: "180717105820000+"

For me the goal is to keep relative time format keep unchanged while
message leaves the kannel.

Any feedback is appreciated. Thanks!

--
Kind regards,
Denis