excel vba - Application.Ontime giving inaccurate results -

when run code below (test1), varying results, around 2.5 sec - 3 secs. understand being higher 3 secs if computer occupied else, less 3 makes no sense. i've tried xl2003 , xl2010, similar results. hope can explain me.

option explicit  dim t double  sub test1()     debug.print     application.ontime + timevalue("00:00:03"), "test2", , true     '  t = timer end sub  sub test2()     debug.print     ' debug.print timer - t end sub 

now() , timer seem update values asynchronously. in quick tests variance ranging approx 0 1 second.

as have discovered should stick 1 source of time. aside, ontime can scheduled in increments of 1 second.