The longest test cricket match lasted 11days and was called off because one team had to catch a boat home
The match mentioned here refers to the Timeless Test played between England and South Africa in the latter in 1939. It seems a combination rainfall and rolling the pitch (i.e. playing surface) rejuvenated the pitch, making it relatively easy to bat on. Combined with some patient batting, this enabled the teams to run up some large scores. Typically the pitch starts to deteriorate after several days play, making it more difficult to bat on.