Initial Time Offset
If Enable Offset is selected, allows you to define a starting time, in minutes offset from the hour.
The default value ( * ) lets you select a starting hour (0 to 23) other than the next hour.
For example:
If you want the task to run every 30 minutes at the :15 and :45 minute mark, you would select Time Interval = 30, Time Interval Units = minutes, and Initial Time Offset = *:15.
If you want the task to run every 30 minutes at the :15 and :45 minute mark starting at 6:15 p.m., you would select Time Interval = 30, Time Interval Units = minutes, and Initial Time Offset = 18:15.