& lwfluxfile, lwfluxstartdate, lwfluxperiod,
_RL lwfluxstartdate
& lwfluxperiod, lwfluxstartdate,
lwfluxstartdate = 0.
call CAL_TOSECONDS ( difftime, lwfluxstartdate ,mythid )
lwfluxstartdate = modelstart + lwfluxstartdate
& lwfluxstartdate