Suppressing reminders

Hi

is there any way to suppress reminders until a specified time before the
reminder is due? My department works a shift pattern so we create
reminders owned by Nobody so whoever is on shift can see what needs to
be done. As the use of RT grows the amount of reminders is getting
bigger and bigger. Ideally I would like to suppress reminders until 24
hours before they are due.

Regards, Jim