Tsc = (Tk) - (Ta)
Where
Tsc = Spawn Camp Time in seconds
Tk = Time you killed them measured in seconds from midnight, January 1, 1970
Ta = Time they arrived at their spawn camp measured in seconds from midnight, January 1, 1970
Ta is a fixed value dependent on when said spawn camper elected to spawn plus any time required to get in position
Tk is entirely in your hands once the spawn is camped
Problem solved.
