Java Utililty Methods Long Number to Time

final String HOURS = "h";
final String MINUTES = "min";
final String SECONDS = "sec";
final long MS_IN_A_DAY = 1000 * 60 * 60 * 24;
final long MS_IN_AN_HOUR = 1000 * 60 * 60;
final long MS_IN_A_MINUTE = 1000 * 60;
final long MS_IN_A_SECOND = 1000;
Date currentTime = new Date();
...

return Long.parseLong(getTimeStr());

return getAmPm(time) + " " + getTimeStr(getHourOf12(time), getMinute(time), true);

String str1 = "";
String str2 = "";
SimpleDateFormat format = new SimpleDateFormat("yy-MM-dd");
Date date = new Date(time);
str2 = format.format(date);
Date newDate2 = new Date(date.getTime() - 7 * 24 * 60 * 60 * 1000);
str1 = format.format(newDate2);
return str1 + "~" + str2;
...

return new Date().getTime() - old;

SimpleDateFormat dt = new SimpleDateFormat("z_yyyy.MM.dd_hh.mm.ss");
dt.setTimeZone(TimeZone.getTimeZone("PST"));
String dateStr = dt.format(new Date(t));
return dateStr;

Date date = new Date(timeLong);
String timeStr = new SimpleDateFormat("yyyyMMddHHmmss").format(date);
return timeStr;

NumberFormat nf = NumberFormat.getInstance(Locale.GERMANY);
float time = nanoTime;
time /= 1000000;
String result = nf.format(time) + " ms";
if (time >= 1000) {
    time /= 1000;
    result += " (" + nf.format(time) + " sec)";
return result;

if (time < 0) {
    return NOT_AVAILABLE_STR;
} else {
    SimpleDateFormat dateFormat;
    TimeZone timeZone = TimeZone.getTimeZone("GMT");
    Calendar calendar = Calendar.getInstance(timeZone);
    calendar.setTimeInMillis(time);
    if (calendar.get(Calendar.HOUR) >= 1) {
...

DecimalFormat format = round ? new DecimalFormat("#") : new DecimalFormat("#.##");
if (getHours(time) >= 1)
    return format.format(getHours(time)) + "h";
else if (Double.valueOf(format.format(getMinutes(time))) >= 1)
    return format.format(getMinutes(time)) + "m";
else
    return format.format(getSeconds(time)) + "s";