CBC Radio One service on 99.1 FM in Calgary will not be available Monday morning.
Maintenance work is being done on the transmission tower which will interfere with the FM signal.
99.1 FM will be off the air from just after midnight until about 5 a.m. MT.
However, listeners can still hear overnight CBC Radio One programming on 1010 AM.
It can also be streamed online at the CBC Calgary website.