Menu fatigue can occur with short cycles. There are several methods to deter this.
Lengthen the cycle. A consumer may remember what the 'Monday' meal is, but is less likely to remember a month-long cycle.
Have an 'odd' number of planned days. That is, a 4, 5, 10 or 20 day cycle will ensure that the same meals do not fall on the same day of the week.
Add interest to the general menu with a 'soup of the day' or 'seasonal vegetables'; this allows for some flexibility in the kitchen, and adds interest for the consumer. This method also allows for different cooking methods of the same foods, or the use of different stock bases. Furthermore, this method allows for minimum waste (e.g., left over vegetables can be made into soup the following day).
Specials can supplement the cyclic menu; special dishes can also be used to take advantage of low cost, or leftover produce.