difference between step time and total time

"abhishek [email protected] [Abaqus]" <[email protected]> Wed, 30 Jan 2019 06:52:09 +0000 (UTC)
Newsgroups gmane.comp.mathematics.abaqus.user
Message-ID <[email protected]>
Hello Respected fellows
i am trying to write a VDLOAD subroutine, in which load need to be distributed as well as vary with respect to time i,e,. my pressure profile have spatial distribution as well as temporal distribution. But i am confused with with step time and total time as my simulation require multiple dynamic explicit steps.
I am giving one example what i understood going through manual, suppose I am doing a 6 step simulation, each even steps (2,4 and 6) is of 1 second and odd steps (1,3 & 5 ) are of 2 seconds... so the total time in the simulation will become 9 seconds.
now when simulation starts for step 1 step time vary from 0 to 2 seconds and total time too will vary from 0 to 2 seconds. but as the 2nd step begins step time will vary from 0 to 1 and total time will vary from 2 to 3 seconds. And so on. 
please explain me how to do multiple step simulation using VDLOAD subroutine. in simulation high pressure shock loading is taking place in step number 1,3 and 5 and step 2,4 & 6 is used to provide damping to the remaining elastic waves in the part. from step 1 to step 3 the position of the shock loading is changing.
For your help i will be very grateful to you.
Thank You 
Abhishek