The sporting event at the Principality Stadium is an annual highlight for Welsh rugby in which all four regions go head-to-head in back-to-back rugby matches in front of an expected crowd of over 60,000 people.
Dragons Vs Scarlets will kick off the highly anticipated tournament at 3pm, before the Cardiff Blues take on the Ospreys at 5.15pm.
Services 1 and 2 will continue to serve Canal Street in the city centre during the rugby road closures.
Bus stop changes will see the Baycar (service 6) starting from Customhouse Street and it will not serve the rear of Central Station or the city centre/Cathays Park loop during the road closure.
Services 8 and 9 to Heath Hospital; 11, 44, 45 and X45 (to St Mellons), 49, 50, 51, 52,
57 and 58 will start from Churchill Way. While the 13 (to Drope), 15, 17, 18, 25, 61, 63, 64, 66, 95, 95A, 96 and 96A will begin at Tudor Street.
The 21, 23, 24, 27, 28, 28A, 28B, 30, 35, 53, will all start from Greyfriars Road. Finally, services 92, 93, and 94 will start at Customhouse Street from 1pm until 7pm and between 7pm and 8pm they will start from Tudor Street.
Lower St Mary Street will remain closed after 8pm, so buses will start to follow their Saturday night diversion in and out of the city centre earlier at 8pm instead of 10pm.
The X59 (Park & Ride East at Pentwyn) will also start and end on Dumfries Place all day on Saturday.
“We would like to remind our customers of route diversions and bus stop alterations in the city centre which will come into effect this Saturday and could impact their journey.
“As such we would urge all those travelling into the city centre on Saturday to plan ahead and check all the travel information before they set off.
“For all the details on our services visit our website and social media channels @CardiffBus for further information, or to call our customer service helpline on 02920 666 444.”