Nullable!DateTime string2dateTime(in string s)
{
    Nullable!DateTime nret;

    if(s.length != "01.01.2018 00:00:00".length) // date like "30.11.-0001 00:00:00"
        return nret; // unknown date

    DateTime r;
    r.date = Date(
        s[6 .. 10].to!short,
        s[3 .. 5].to!ubyte,
        s[0 .. 2].to!ubyte
    );
    r.timeOfDay = TimeOfDay.fromISOExtString(s[11 .. 19]);

    nret = r;

    return nret;
}