How can i use Spotlight on Oracle to find out the number of oracle connections for a particular date and time
Spotlight on Oracle has a History browser to view historical data, but by design Spotlight does not show data for Top Session in History mode.
In general, Spotlight only logs history for data that is being refreshed continuously (there are a couple of exception to this, but the TopSessions drill down isn't one of them).
Also, Spotlight must be connected to gather history information. Spotlight queries the OS and database using to gather information ; it has no agents running so no data is collected in history when disconnected.