You are missing the time zone in the date format at the end, in your exception message, in the "CEST" part. Your code
DateFormat df = new SimpleDateFormat("EEE, dd MMM yyyy kk:mm:ss", Locale.getDefault());
it should be
DateFormat df = new SimpleDateFormat("EEE, dd MMM yyyy kk:mm:ss z", Locale.getDefault());
You might want to read SimpleDateFormat
Change At the bottom of this page, the time zone format is clearer. A clearer time zone format
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