Somewhat stupid drug test question…

[Smitty2]

This might sound like a dumb question, but are detection times based on last usage, or are they cumulative? What SWIM means by this is let’s say he is not a regular user, but used a small amount of Cocaine on both Wednesday and Thursday of this week and detection times are said to be 48-72 hours after, well does this mean after the last “dose” of the drug, in this case 78 hours from Thursday, or does this mean that the detection time will now be double of that, IE 96 to 156 hours since SWIM used two days in a row? SWIM is pretty sure it just goes by last dose, so in this case if SWIM only used on Weds it would be gone by Sun, but now since he used Thurs it will be gone by Mon.