@twistedpixels sorry for the late answer, yes, you need to do something like this:
set serpentine to run for 60 seconds (endTime="60")
then set filler to run for 30 seconds but start after 60 seconds (startTime="60" endTime="30")
then set pulse to start after 90 seconds and run for 60 (startTime="90" endTime="30")

I think they will repeat, but let me know if not!