...
OS_Alm, alarm manipulation (OZ usage)
GN_Aab, allocate alarm block
GN_Alp, process an expired alarm
GN_Fab, free alarm block
GN_Gab, get first alarm block
GN_Lab, link an alarm block into the alarm chain
GN_Uab, unlink an alarm block from the alarm chain
Application
DC_Nam, Name current application
OS_Poll, poll for an application (OZ usage)
DC_Pol, poll for card usage
OS_Ent, enter an application (OZ usage)
DC_Ent, enter new application (low level OZ usage)
OS_Exit, exit an application (OZ usage)
DC_Bye, exiting current application (OZ usage)
OS_Bye, exit application
OS_Stk, stack current process / application (OZ usage)
OS_Use, process card usage (OZ usage)
...
GN_Gdt, convert ASCII to internal date
GN_Dei, convert zoned format date to internal format
GN_Die, convert internal format date to zoned format
GN_Gmd, get (read) machine date in internal format
GN_Ldm, Country localized date manipulation (OZ 4.5 and newer)
GN_Pdt, write internal date as ASCII string
GN_Pmd, put (set) machine date
...