VMS Help SUBMIT, Qualifiers, /AFTER  *Conan The Librarian (sorry for the slow response - running on an old VAX)

       /AFTER=time
       /NOAFTER

    Requests that the job be held until after a specific time. If
    the specified time has passed already, the job is processed
    immediately.

    You can specify time as either absolute time or as a combination
    of absolute and delta times. For complete information on
    specifying time values, refer to the OpenVMS User's Manual or
    the online help topic DCL_Tips (subtopic Date_Time).

    In an OpenVMS Cluster, a batch job submitted to execute at a
    specific time may begin execution a little before or after the
    requested time. This occurs when the clocks of the member systems
    in the OpenVMS Cluster are not synchronized. For example, a job
    submitted using the DCL command SUBMIT/AFTER=TOMORROW may execute
    at 11:58 P.M. relative to the host system's clock.

    This problem can occur in a cluster even if a job is run on
    the same machine from which it was submitted, because the
    redundancy built into the batch/print system allows more than
    one job controller in the cluster to receive a timer asynchronous
    system trap (AST) for the job and, thus, to schedule it for
    execution. Moreover, this behavior is exacerbated if the batch
    job immediately resubmits itself to run the next day using the
    same SUBMIT command. This can result in having multiple instances
    of the job executing simultaneously because TOMORROW (after
    midnight) might be only a minute or two in the future.

    A solution to this problem is to place the SUBMIT command in
    a command procedure that begins with a WAIT command, where
    the delta-time specified in the WAIT command is greater than
    the maximum difference in time between any two systems in the
    cluster. Use the SHOW TIME command on each system to determine
    this difference in time. Use the SYSMAN command CONFIGURATION
    SET TIME to synchronize clocks on the cluster. For complete
    information on the SYSMAN command CONFIGURATION SET TIME, refer
    to the OpenVMS System Management Utilities Reference Manual.