HSDIO Advance trigger

In the example to HSDIO Dynamic Acquisition of Multiple Records.vi used Advance trigger. I have some questions on its application:
1). If we have a trigger, for example, which appears with a frequency of 1 MHz, data each time (when front appears) are received, i.e. there are no gaps in the data acquiring? Can it happen that we will acquire data on the 1st trigger, 5th, 9th, and so on?
2).  What is absolute timestamp in waveform information? This is the start time of each record HSDIO?