The clash was due to take place on Friday night but has now been pushed back a day to Saturday due to the original timing clashing with the visit of King Charles III to Cardiff. The rearranged fixture will kick off at 15:05 BST and remains live on BBC Two Wales and Premier Sports.
A URC statement said: “Originally due to take place on Friday night (19:35), significant logistical challenges have occurred due to the visit of HRH King Charles III and the Queen’s Consort to Cardiff on September 16.
“Broadcast facilities for both the host broadcaster (BBC Wales) and other TV facilities providers will be engaged in the coverage of the visit and the drain on available resources has resulted in the rescheduling of the game.
“The BKT United Rugby Championship would like to thank both Cardiff and Munster for their understanding in this matter which has occurred under very unique circumstances. It is also appreciated that BBC Wales made every effort to keep the fixture in its original date and time slot.
“The Cardiff v Munster will be broadcast live on BBC Wales, RTÉ 2, Premier Sport, SuperSport and URC.tv.” Cardiff RFC were already scheduled to face Merthyr in the Welsh Cup on Saturday but that fixture has been brought forward to 11:45am to allow back to back fixtures at the Arms Park.
Numerous options for the Cardiff RFC fixture were explored, however the 11:45am was the only kick-off time was the only option available to allow a double-header. Tickets for Cardiff versus Munster will grant access to both games and all tickets purchased for Friday night remain valid for Saturday.
Refund options will be communicated directly to ticket holders in due course.