You can change the automatic dump start window at any time, even when automatic dump is currently running on the particular DFSMShsm host. Automatic dump runs when the new planned start time occurs if the currently running automatic dump completes before the planned start time of your newly defined start window. If the currently running automatic dump runs past the new planned start time, automatic dump will not start automatically until the next time the planned start time occurs. However, if automatic dump is released or DFSMShsm is restarted during the newly defined automatic dump start window, automatic dump starts unless it is prevented by one of the commands discussed in Interrupting and restarting automatic dump processing or by denying permission to the SETSYS REQUEST command.