On 2AM on March 28th 2014, Israel went from standard time (GMT+2) to daylight saving time (GMT+3).
The server's timezone is Asia/Jerusalem. When creating a partition whose key is 2014-03-28, Hive creates a partition for 2013-03-27 instead:
hive (default)> create table test (a int) partitioned by (`b_prt` date);
Time taken: 0.092 seconds
hive (default)> alter table test add partition (b_prt='2014-03-28');
Time taken: 0.187 seconds
hive (default)> show partitions test;
Time taken: 0.134 seconds, Fetched: 1 row(s)
It seems that the root cause is the behavior of DateWritable.daysToMillis/dateToDays.