Using the following data:
$cat date1.csv
Bob,2013-06-03T17:18:07
James,2013-06-03T17:18:07
Kevin,2013-06-03T17:18:07
$cat date2.csv
2012-12-02T18:30:31
Another way of doing it is with pr
pr -mts, file1 file2
[jaypal:~/Temp] cat file1
Bob,2013-06-03T17:18:07
James,2013-06-03T17:18:07
Kevin,2013-06-03T17:18:07
[jaypal:~/Temp] cat file2
2012-12-02T18:30:31
2012-12-02T18:28:37
2013-06-01T12:16:05
[jaypal:~/Temp] pr -mts, file1 file2
Bob,2013-06-03T17:18:07,2012-12-02T18:30:31
James,2013-06-03T17:18:07,2012-12-02T18:28:37
Kevin,2013-06-03T17:18:07,2013-06-01T12:16:05