ðə dˈɑːktɚ hˌuː ɹˈɛfɹəns ɡˈaɪd sədʒˈɛsts ðætðə plˈænɪt hˈɛɹɪɾɪdʒ wʌz jˈuːzɪŋ ɐ nˈɑːnstˈændɚd dˈeɪɾɪŋ sˈɪstəm.
The Doctor Who Reference Guide suggests that the planet Heritage was using a non-standard dating system.