@NonNull
    public static String formatDaysAgo(final long date) {
        final int days = CalendarUtils.daysSince(date);
        return CgeoApplication.getInstance().getResources().getQuantityString(R.plurals.days_ago, days, days);
    }
Generate a numeric date and time string according to system-wide settings (locale,
date format) such as "7 september at 12:35".

@param date milliseconds since the epoch
@return the formatted string
main/src/main/java/cgeo/geocaching/utils/Formatter.java