time bomb

( n.)

   A  subspecies  of  {logic  bomb}  that  is triggered by reaching some
   preset  time, either once or periodically. There are numerous legends
   about  time bombs set up by programmers in their employers' machines,
   to  go  off if the programmer is fired or laid off and is not present
   to perform the appropriate suppressing action periodically.

   Interestingly,  the only such incident for which we have been pointed
   to  documentary  evidence  took  place in the Soviet Union in 1986! A
   disgruntled  programmer at the Volga Automobile Plant (where the Fiat
   clones  called  Ladas were manufactured) planted a time bomb which, a
   week  after  he'd  left on vacation, stopped the entire main assembly
   line  for  a  day. The case attracted lots of attention in the Soviet
   Union  because  it  was  the  first cracking case to make it to court
   there.  The  perpetrator  got a suspended sentence of 3 years in jail
   and was barred from future work as a programmer.

[glossary]