wish
do TCL pode resolver isso prontamente
#!/usr/bin/env wish8.5
set intervalms 1
variable theclock
proc setclock {} {
global intervalms theclock
set micros [clock microseconds]
set epoch [expr $micros / 1000000]
set micros [format "%06d" [expr $micros % 1000000]]
set theclock [clock format $epoch -format "%a %b %d %Y %H:%M:%S.$micros"]
after $intervalms [list setclock]
}
font create TtyFont -family Courier -size 16 -weight bold
pack [label .clock -font TtyFont -textvariable theclock]
grid .clock -row 1 -column 1
grid rowconfigure . 1 -weight 1
grid columnconfigure . 1 -weight 1
wm geometry . 400x60+0+0
setclock
Mas se incomodar for seu objetivo ...