Such customization of the RecurrenceEditor is not supported. It is designed to be used in the Scheduler and time could be relevant only for the Hourly recurrence, otherwise if a Daily or a Weekly, etc. recurrence is selected specifying time is not needed, thus it is not added as an option to select. The implementation for the Hourly recurrence also does not need a TimePicker, since it gets the information on when the recurrence ends from the End By date, the recurrence frequency (Recur every ... hour(s)) and the Appointment's End Time.
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