Some reports in SiteLink are designed to be viewed explicitly for a certain type of period and cannot be generated for other periods in a way that makes sense.
For example, the Occupied History report is designed to give occupancy details month-by-month for a 1 year period, starting backward from the chosen month. Daily and Weekly period options cannot be extrapolated from this, and annual-related options would be redundant.
As another example, Unpaid Charges is designed to show a list of ALL tenants with *currently* unpaid charges and the age of those charges. Choosing a date for Unpaid Charges would invalidate the intent of the report. If you require information about unpaid balances for a specific period you can try using other reports like Accounts Receivable or Aged Receivables which allow for date selection.