Agilent Technologies 1660A Series User Reference page 182

The Format Menu
Setup/Hold Field (State only)
The relationship of the clock signal and valid data under the default setup
and hold is shown in the figure below.
Default Setup and Hold
If the relationship of the clock signal and valid data is such that the data is
valid for 1 ns before the clock occurs and 3 ns after the clock occurs, you will
want to use the 1.0 setup and 2.5 hold setting.
Clock Position in Valid Data
11–24