以下是常用的格式化字符串：

y Year Year

M Month in year Month

w Week in year Number

W Week in month Number

D Day in year Number

d Day in month Number

F Day of week in month Number

E Day in week Text

a Am/pm marker Text

H Hour in day (0-23) Number

k Hour in day (1-24) Number

K Hour in am/pm (0-11) Number

h Hour in am/pm (1-12) Number

m Minute in hour Number

s Second in minute Number

S Millisecond Number

z Time zone General time zone

Z Time zone RFC 822 time zone

以下是两个示例：

public static String getGmtDate() {
	DateFormat df = new SimpleDateFormat("d MMM yyyy HH:mm:ss z", Locale.ENGLISH);
	df.setTimeZone(TimeZone.getTimeZone("GMT"));
	return (df.format(new Date()));
}
public static String getUtcDate() {
	DateFormat gmtFormat = new SimpleDateFormat("yyyyMMdd'T'HHmmss.SSS'Z'");
	Calendar calendar = java.util.Calendar.getInstance();
	return gmtFormat.format(calendar.getTime());
}