 Time fuzes detonate after a set period of time by using one or more combinations of mechanical, electronic, pyrotechnic or even chemical timers.Depending on the technology used, the device may self-destruct (or render itself safe without detonation) some seconds, minutes, hours, days, or even months after being deployed.Early artillery time fuzes were nothing more than a hole filled with gunpowder leading from the surface to the centre of the projectile.