Normally a transfer forwarded to the XCOM Server (called a scheduled transfer) is processed immediately. XCOM provides two parameters which allow specifying a specific day and time at which the transfer is to be processed.
These parameters are START_DATE and START_TIME. In the Unix XCOM GUI you can specify the desired day and time for a scheduled transfer in the section "Misc Options" in field 'START'. You can specify day and time directly using format "mm/dd/yy hh:mm:ss" or click on the calendar symbol to select from the incorporated calendar.
When using the command xcomtcp you specify
There are alias parameters STARTDATE and STARTTIME available which allow different formats:
STARTDATE=yyyymmdd (20151231 represents Dec. 31st, 2015)
STARTDATE=yyddd (Julian date, 16001 represents the first day of 2016)
STARTDATE=+nnn (nnn days from today, nnn in the range from 0 to 999)
STARTTIME=hhmm (1300 represents 1 pm)
STARTTIME=+hhmm (+0330 represents start in three and a half hour)