How to use NEXT_TRANSMISSION value from homematic PIR sensors?

Hi,
I tried to use the NEXT_TRANSMISSION value from homegear:

homegear-log

02/06/17 09:49:40.536 Module HomeMatic BidCoS: Info: NEXT_TRANSMISSION on channel 1 of HomeMatic BidCoS peer 24 with serial number NEQxxxxxxx was set to 0x08

I read that next_transmission should be handled as datetime.

I tried to use it as datetime…

DateTime eg_pir_aussen_next				"Nächste Übertragung [%1$td.%1$tm. %1$tT]" <calendar> 	(debug)	{homematic="address=NEQxxxxxxx, channel=1, parameter=NEXT_TRANSMISSION"}

But it does not work:

2017-02-06 09:49:40.639 [WARN ] [h.i.converter.ConverterFactory] - Can't find converter for DatapointConfig[address=NEQxxxxxxx,channel=1,parameter=NEXT_TRANSMISSION], value is not published!

Who has some hints for me? How can I work with the next transmission data?