timepicker not working for base search in dashboard

Hi, we added timepicker to a simple dashboard consists of base search as following, but it's not working. Using full search in panels the timepicker works properly. Would anyone please help? We're using 6.5.4. Thanks a lot.

Dashboard 1sourcetype=syslog$time_tok1.earliest$$time_tok1.latest$

-1mon@mon@mon

stats count by Type$time_tok1.earliest$$time_tok1.latest$