 The duration of Djedkare 's reign is much less certain . Djedkare 's time on the throne is well documented by the Abusir papyri , numerous royal seals and contemporary inscriptions ; taken together , they indicate a fairly long rule for this king . While the Turin canon credits him with 28 years of reign , there is direct evidence for an even longer reign . Several artefacts and inscriptions have been uncovered relating to Djedkare 's <unk> or " sed " festival , normally celebrated only after 30 years of reign . For example , the tomb of one of Djedkare 's viziers , Senedjemib Inti , relates construction works undertaken during the year of the 16th cattle count in preparation for the festival ceremonies . An alabaster vase now on display at the Louvre museum bears an inscription celebrating Djedkare 's first sed festival , indicating in all likelihood that he reigned beyond his 30th year on the throne . 
