private void checkChar(String s, int spos, char expected) {
    char c = s.charAt(spos);
    if (c != expected) {
        throw new TimeFormatException(String.format(
                "Unexpected character 0x%02d at pos=%d.  Expected 0x%02d (\'%c\').",
                (int) c, spos, (int) expected, expected));
    }
}
 

private static int getChar(String s, int spos, int mul) {
    char c = s.charAt(spos);
    if (Character.isDigit(c)) {
        return Character.getNumericValue(c) * mul;
    } else {
        throw new TimeFormatException("Parse error at pos=" + spos);
    }
}
 

@Override
public int parsePart(String value, EventRecurrence er) {
    if (VALIDATE_UNTIL) {
        try {
            // Parse the time to validate it.  The result isn't retained.
            Time until = new Time();
            until.parse(value);
        } catch (TimeFormatException tfe) {
            throw new InvalidFormatException("Invalid UNTIL value: " + value);
        }
    }
    er.until = value;
    return PARSED_UNTIL;
}
 

public static Time timeFrom3339(String s3339) {
    final Time time = new Time();
    if (TextUtils.isEmpty(s3339)) {
        return time;
    }
    try {
        time.parse3339(s3339);
    } catch (TimeFormatException e) {
        return time;
    }
    time.switchTimezone(Time.getCurrentTimezone());
    return time;
}
 

public static Time timeFrom3339(String s3339) {
    final android.text.format.Time time = new Time();
    if (TextUtils.isEmpty(s3339)) {
        return time;
    }
    try {
        time.parse3339(s3339);
    } catch (TimeFormatException e) {
        return time;
    }
    time.switchTimezone(android.text.format.Time.getCurrentTimezone());
    return time;
}
 

@Override
public int parsePart(String value, EventRecurrence er) {
    if (VALIDATE_UNTIL) {
        try {
            // Parse the time to validate it.  The result isn't retained.
            Time until = new Time();
            until.parse(value);
        } catch (TimeFormatException tfe) {
            throw new InvalidFormatException("Invalid UNTIL value: " + value);
        }
    }
    er.until = value;
    return PARSED_UNTIL;
}
 

/**
 * Parse a time in the current zone in YYYYMMDDTHHMMSS format.
 */
private boolean parseInternal(String s) {
    int len = s.length();
    if (len < 8) {
        throw new TimeFormatException("String is too short: \"" + s +
                "\" Expected at least 8 characters.");
    }

    boolean inUtc = false;

    // year
    int n = getChar(s, 0, 1000);
    n += getChar(s, 1, 100);
    n += getChar(s, 2, 10);
    n += getChar(s, 3, 1);
    year = n;

    // month
    n = getChar(s, 4, 10);
    n += getChar(s, 5, 1);
    n--;
    month = n;

    // day of month
    n = getChar(s, 6, 10);
    n += getChar(s, 7, 1);
    monthDay = n;

    if (len > 8) {
        if (len < 15) {
            throw new TimeFormatException(
                    "String is too short: \"" + s
                            + "\" If there are more than 8 characters there must be at least"
                            + " 15.");
        }
        checkChar(s, 8, 'T');
        allDay = false;

        // hour
        n = getChar(s, 9, 10);
        n += getChar(s, 10, 1);
        hour = n;

        // min
        n = getChar(s, 11, 10);
        n += getChar(s, 12, 1);
        minute = n;

        // sec
        n = getChar(s, 13, 10);
        n += getChar(s, 14, 1);
        second = n;

        if (len > 15) {
            // Z
            checkChar(s, 15, 'Z');
            inUtc = true;
        }
    } else {
        allDay = true;
        hour = 0;
        minute = 0;
        second = 0;
    }

    weekDay = 0;
    yearDay = 0;
    isDst = -1;
    gmtoff = 0;
    return inUtc;
}