The low heel and open tabs are typical of walking shoes, the fleece lining is for winter wear, and the well worn sole suggests to me they were worn a lot, so perhaps they are part of a uniform like a delivery or mailman. They aren't fashion per se, so there is nothing specific to date them by - they have no elongated toe or shaped heel - they are utilitarian and as such are difficult to date accurately. I wouldn't put them before the mid 50s, nor after the early 90s, but I suspect they are probably early 60s, and because they are German, their styling is a bit unusual too - normally you would see boots for uniforms in Britain and the U.S. in the 60s, not shoes, but the dressy look of these with the well worn sole are a bit odd. I could see them being worn with heavy socks and knickers - very trachtenkleide looking.