Are variables of type realtime rounded-off based on timeprecision?

In reply to dave_59:

rtdelay stores the real value 800.559. Time scales and precision only apply to expressions using in delay constructs. Not until the appearance of #rtdelay do the scaling and precision apply

Thanks Dave ,
The above quotes does explain the scaling and precision part .

However I am still confused about the following :
(a) In (1) the value assigned 800.559 is a real no. which is unitless
In (2) the value assigned 800.559 is a real no. which has a unit of ps.

 **Does  the  unit  make  a  difference  in  what  gets  stored  in  variable  rtdelay  in 2nd  case ?**  

(b) How does the format specifier %t work with rtdelay as argument in both cases ?

 In  (1)  the  value  assigned  to  rtdelay  is  800.559 .  
 It  seems  that  it  takes  this  to  be  in  units  of  ns  and  it  simply  converts  it  to  ps  in  the  output i.e  multiplies it by 1000

Similarly I am not fully clear on how 801 is shown in output for (2)