test_datetime passes here with nearly identical conditions as on the CI (Ubuntu 14.04, clang, same random seed):

Using random seed 987845
Run tests in parallel using 4 child processes
0:00:01 load avg: 1.70 [  1/415] test_html passed
0:00:01 load avg: 1.88 [  2/415] test_unicode_file_functions passed
0:00:02 load avg: 1.88 [  3/415] test_rlcompleter passed
0:00:03 load avg: 1.88 [  4/415] test_xml_etree passed
0:00:03 load avg: 1.88 [  5/415] test_codecencodings_kr passed
0:00:03 load avg: 1.88 [  6/415] test_dummy_thread passed
0:00:04 load avg: 1.88 [  7/415] test_source_encoding passed
0:00:05 load avg: 1.88 [  8/415] test_code passed
0:00:05 load avg: 1.88 [  9/415] test_curses passed
0:00:06 load avg: 1.88 [ 10/415] test_sys_setprofile passed
0:00:07 load avg: 2.05 [ 11/415] test_getopt passed
0:00:08 load avg: 2.05 [ 12/415] test_atexit passed
0:00:09 load avg: 2.05 [ 13/415] test_shlex passed
0:00:13 load avg: 2.13 [ 14/415] test_epoll passed
0:00:14 load avg: 2.13 [ 15/415] test_fileinput passed
0:00:26 load avg: 2.42 [ 16/415] test_embed passed
0:00:30 load avg: 2.54 [ 17/415] test_resource passed
0:00:31 load avg: 2.54 [ 18/415] test_augassign passed
0:00:36 load avg: 2.77 [ 19/415] test_gc passed -- running: test_io (33 sec)
0:00:38 load avg: 2.77 [ 20/415] test_multibytecodec passed -- running: test_io (35 sec)
0:00:38 load avg: 2.77 [ 21/415] test_contextlib passed -- running: test_io (35 sec)
0:00:39 load avg: 2.77 [ 22/415] test_code_module passed -- running: test_io (36 sec)
0:00:50 load avg: 2.80 [ 23/415] test_select passed -- running: test_unicodedata (36 sec), test_io (47 sec)
0:00:51 load avg: 2.90 [ 24/415] test_posixpath passed -- running: test_unicodedata (37 sec), test_io (48 sec)
0:01:05 load avg: 3.07 [ 25/415] test_capi passed -- running: test_unicodedata (50 sec), test_io (62 sec)
0:01:06 load avg: 3.07 [ 26/415] test_string passed -- running: test_unicodedata (52 sec), test_io (63 sec)
0:01:08 load avg: 3.06 [ 27/415] test_unicodedata passed (52 sec) -- running: test_io (65 sec)
0:01:09 load avg: 3.06 [ 28/415] test_iter passed -- running: test_io (66 sec)
0:01:09 load avg: 3.06 [ 29/415] test_largefile passed -- running: test_io (66 sec)
0:01:10 load avg: 3.06 [ 30/415] test_xxtestfuzz passed -- running: test_io (67 sec), test_datetime (30 sec)
0:01:10 load avg: 3.06 [ 31/415] test_pkg passed -- running: test_io (67 sec), test_datetime (31 sec)
0:01:11 load avg: 3.06 [ 32/415] test_datetime passed (30 sec) -- running: test_io (67 sec)