DateFormat.format では HH:mm が使えない ref: http://qiita.com/items/b33603b958a4d0eedc8a

DateTimeFormatTest.java

long t = System.currentTimeMillis();
Log.d("By DateFormat", DateFormat.format("HH:mm", t).toString());
Log.d("By SimpleDateFormat", new SimpleDateFormat("HH:mm").format(new Date(t)));

file1.txt

04-09 22:42:14.435: D/By DateFormat(2860): HH:42 ←あ〜あ
04-09 22:42:14.435: D/By SimpleDateFormat(2860): 22:42