Ar 21 Medi 2016, cyhoeddodd Comisiwn Staff y Gwasanaethau Cyhoeddus egwyddorion a chanllawiau ar ddefnydd priodol o drefniadau oriau heb eu gwarantu mewn gwasanaethau cyhoeddus datganoledig yng Nghymru.  Mae'r trefniadau'n cynnwys contractau dim oriau.
On 21 September 2016 the Public Services Staff Commission published their principles and guidance on the appropriate use of non guaranteed working hours arrangements in devolved public services in Wales.  Non guaranteed hours arrangements will encompass zero hour contracts.