Hmm I can not seem to get this to work. Perhaps its not possible but take a look at this CALL:X
THe expressions by themself work fine… but the CALL is not getting the correct data for some reason so I think it has to do with this expression and all the nested tags.
{CALL:Time.eta("[=FD(ADS('{TICKET TIME}',TN('{SETTING:{TICKET NO}}')*60),'HH:mm')]","[=FD('{TIME}','HH:mm')]")}