Show me in ISO 19011:2002 where there is a requirement for a schedule.
All you'll find is references to schedules as a "should" and not a "shall" in Section 5.
The need for audit schedules will be detailed in the "Specification" or "Requirements" standards for the various management systems.
Therefore the answer coould be yes or it could be no.
Please note the extra 'o' in coould - Arkansas emphasis placed there........