static private int printField(char[] formatStr, int amt, char suffix, int pos,
                                  boolean always, int zeropad) {
        if (always || amt > 0) {
            final int startPos = pos;
            if ((always && zeropad >= 3) || amt > 99) {
                int dig = amt / 100;
                formatStr[pos] = (char) (dig + '0');
                pos++;
                amt -= (dig * 100);
            }
            if ((always && zeropad >= 2) || amt > 9 || startPos != pos) {
                int dig = amt / 10;
                formatStr[pos] = (char) (dig + '0');
                pos++;
                amt -= (dig * 10);
            }
            formatStr[pos] = (char) (amt + '0');
            pos++;
            formatStr[pos] = suffix;
            pos++;
        }
        return pos;
    }
@hide Field length that can hold 999 days of time
android/android_framework/base/src/main/java/github/tornaco/android/thanos/core/util/TimeUtils.java