Guardian Procedure Calls Reference Manual

December 1974. Note that this is not a Julian timestamp and therefore it is not transferable
across HP systems. Applications should avoid using the RCLK instruction except where
necessary.
• Process timing uses 64-bit elapsed time counters with microsecond resolution; these are also
not Julian timestamps.
• There is no way to generalize about internal timing using 64-bit Julian timestamps or 48-bit
timestamps. Each section of the operating system manages time using the method most
appropriate for its application.
• The time representations GMT, LST, and LCT are described in the Time Zones and Daylight
Saving Time section of the Guardian Programmer's Guide.
NOTE: Because processor clocks are not synchronized to the nearest microsecond, values obtained
from different processors might not agree.
• The value returned by JULIANTIMESTAMP(3), a count of the number of microseconds since
COLDLOAD of this processor, is affected by adusting but not by setting the time (see the
SYSTEMCLOCK_SET_ Procedure (page 1408) for time setting or adjustment). Therefore the
calculation: JULIANTIMESTAMP(0) - JULIANTIMESTAMP(1) (current time) - (cold load time) will
not always match what is returned by JULIANTIMESTAMP(3).
Example
MY^TIME := JULIANTIMESTAMP; ! returns the current GMT
Related Programming Manual
For programming information about the JULIANTIMESTAMP procedure, see the Guardian
Programmer's Guide.
JULIANTIMESTAMP Procedure 749