but when i change to operator to >= i faces with connection time out
Is this change applied to all the predicates or just one?
Would you please examine the generated queries in both cases (before and after the change), and manually run them directly against the database to see if the same problem occurs on the database side.
To get the generated query, please consult the manual's section "Using the generated code -> Troubleshooting and debugging"
Also please post the generated queries here. If you could not sort out the problem.