So do it properly.
Look at using NTP to sync your clock permanently. Unless you have a
terminally broken clock (and some systems are beyond fixing), this will
permanently sync your clock including adding an overall adjustment to the
system tick period.
Info on NTP is available at
http://www.eecis.udel.edu/~ntp/
Nigel.
-- [ Nigel.Metheringham@theplanet.net - Systems Software Engineer ] [ Tel : +44 113 251 6012 Fax : +44 113 234 6065 ] [ Real life is but a pale imitation of a Dilbert strip ]