I received this beautiful QSL card DCF77 Time-Signal on 77.5 kHz by mail. The transmitter is located in Mainflingen, Germany. The QSL was accompanied by a folder on how time is managed. I also received a 2009 magazine from the PTB (Physikalisch-Technischen Bundesanstalt) with a special topic on 50 years of DCF77. This magazine is also available online. I sent my report to firstname.lastname@example.org .
As you can read on the QSL there is no voice announcement of the time. Instead the date and time are transmitted by in code through the interval between second markers (0.1 s = “zero”; 0.2 s = “1”). You can see this in my waterfall map below. The gap prior to second 53 and 57 is twice as big. At the minute there is no gap.