WWRB, Morrison TN, USA current UTC schedule based on their website schedule (below) is:
2300 UTC (Sat) - 0200 UTC (Sun) on 3215kHz
2300 UTC (Sun) - 0200 UTC (Mon) on 3215kHz
0200 UTC (Sun) - 0500 UTC (Mon) on 3185 kHz
0200 UTC (Mon) - 0500 UTC (Mon) on 3185 kHz
(WWRB only use one transmitter and so 5050 kHz now not used it seems. WWCR also use 3215, but from 0200 when WWRB switches to 3185)
WWRB heard here at 0000 UTC on 3215 and just after 0200 UTC on 3185, confirming above.
Current Broadcasting Schedule
Global 1, Service 1:
Saturday and Sunday - 6:00 pm EST - 9:00 pm EST on shortwave frequency 3.215 MHz
Saturday and Sunday - 9:00 pm EST to 12:00 am EST on shortwave frequency 3.185 MHz
Coverage to North, Central, South America, with enhanced Cuba/Caribbean Coverage
http://www.wwrb.org/
(Alan Pennington via bdxc-news io group)