Regarding |date_time| and |query_ifIP|

[amol]

I have configured my cacti all is working fine but when i entered |date_time| in title field of graphs its not giving me a updated date and time.
Acording to cacti manual it should show me a date and time of the last poller run on the graph.
|query_ifIP|is also not working and display directly on a graph header as
|date_time|-traffic-|query_ifIP|.
Please reply as early as possible.