Cyclostratigraphy is a popular method that promises much more precise dates than biostratigraphy or radioisotope dating. Originally, it was pioneered to date Pleistocene glacial/interglacial intervals, but its reach has been steadily extended back through the Cenozoic and into earlier eras using sedimentary cycles. Unfortunately, enthusiasm for its potential has blinded geologists to its problems. Six problems are addressed, revealing the influence of subjective factors not commonly noticed.