Hive date function to achieve day of week

You can now use date_format (Hive 1.2):

hive> select date_format('2016-12-01' ,'u');
OK
4

Consider using from_unixtime(your date,'u') - this will return day number of week starting from Monday=1. If your date is not in unixtime format, you can use the following instead:

from_unixtime(unix_timestamp('20140112','yyyyMMdd'),'u')

see: http://docs.oracle.com/javase/7/docs/api/java/text/SimpleDateFormat.html for simple date format documentation.