UK-based satellite/Internet station Radio Caroline announces on its website that “from Thursday, 7th September listeners living in Latvia and its surrounding area will once again be able to tune to Caroline on mediumwave, when each Thursday evening between 9pm and midnight Rob Leighton’s Imagination programmes are relayed through the transmission facilities of Radio Nord. Radio Nord broadcasts to Latvia’s capital city Riga, and boasts an audience of 100,000.” The frequency is 945 kHz. We presume the time mentioned is UK time, so that would be 2000-2300 UTC.
(Source: R Netherlands Media Network Weblog)