hold time dbt
For a normal reg to reg path, the data is launched from the launch flop at a clock edge (call it x) and captured at the capture flop at the NEXT clock edge (x+1). If the clock delay to the capture flop is GREATER than the clock delay to launch flop + data delay then you will violate hold.
In other words, data launched at clock edge x must not be captured at capture flop by the same clock edge x, it should be captured by the next clock edge x+1.
This is why the launch edge and capture edge for hold checks are the same. Since the edges are the same, changing the frequency has no effect.