Verilator で、initial 文 + #　が使えるね

module test;

timeunit 1ns;
timeprecision 1ps;

initial begin
$timeformat(-9, 3, " ns", 12);
#1;
$display("%t", $realtime);
#3;
$display("%t", $realtime);
end

endmodule

$ verilator test --binary --timing

make: Leaving directory '/mnt/c/Users/haray/home/tmp/verilator/obj_dir'
- V e r i l a t i o n   R e p o r t: Verilator 5.032 2025-01-01 rev UNKNOWN.REV
- Verilator: Built from 0.024 MB sources in 2 modules, into 0.020 MB in 7 C++ files needing 0.000 MB
- Verilator: Walltime 5.637 s (elab=0.000, cvt=0.009, bld=5.567); cpu 0.007 s on 1 threads; alloced 18.996 MB

$ obj_dir/Vtest
    1.000 ns
    4.000 ns
- S i m u l a t i o n   R e p o r t: Verilator 5.032 2025-01-01
- Verilator: end at 4ns; walltime 0.000 s; speed 4.927 us/s
- Verilator: cpu 0.001 s on 1 threads; alloced 56 MB