private List<DateFormat> loadDateFormats() {
        List<DateFormat> dateFormats = new ArrayList<>();
        // yyyy-mm-ddThh...
        dateFormats.add(createDateFormat("yyyy-MM-dd'T'HH:mm:ss'Z'", UTC));   // UTC/Zulu
        dateFormats.add(createDateFormat("yyyy-MM-dd'T'HH:mm:ssZ", null));    // With timezone
        dateFormats.add(createDateFormat("yyyy-MM-dd'T'HH:mm:ss", null));     // Without timezone
        // yyyy-mm-dd hh...
        dateFormats.add(createDateFormat("yyyy-MM-dd' 'HH:mm:ss'Z'", UTC));   // UTC/Zulu
        dateFormats.add(createDateFormat("yyyy-MM-dd' 'HH:mm:ssZ", null));    // With timezone
        dateFormats.add(createDateFormat("yyyy-MM-dd' 'HH:mm:ss", null));     // Without timezone
        // Date without time, set to Midday UTC
        dateFormats.add(createDateFormat("yyyy-MM-dd", MIDDAY));       // Normal date format
        dateFormats.add(createDateFormat("yyyy:MM:dd",
                MIDDAY));              // Image (IPTC/EXIF) format

        return dateFormats;
    }
Returns ISO-8601 formatted time converted to UTC, truncated to the seconds place
@param calendar
@return
tika-core/src/main/java/org/apache/tika/utils/DateUtils.java