Need to Display a warning message during specific time for example 8:30 AM Daily PST

What's the outcome you want to achieve here? What will the "freeze" achieve? What will it prevent users from doing? (I'm asking because I wonder if there are other options available to you)

What's the outcome you want to achieve here? What will the "freeze" achieve? What will it prevent users from doing? (I'm asking because I wonder if there are other options available to you)

We have a process model running at 8:30 AM daily which will perform some updates in the database, during that time we need to display some X interface saying " some process is running in the background please access after 5 minutes ". After 5 minutes we can show the home page. How can we achieve this.

Ok - is the purpose of that message to dissuade (prevent?) users from conducting any actual actions? Or to indicate that the data they're viewing might be stale? Something else? 

Thank you Stewart, here when users are accessing home screen during the background process is executing some update statements at the same time users are accessing homepage, this is causing deadlock situation. how can we prevent this situation by using some warning message 

Ok, so I think there are two distinct things here:

1. your primary motivation/requirement is to prevent users from running actions that conflict with the background update that is in progress
2. you want to display a notice that says users cannot currently conduct updates whilst the background process is running

For the first you could add to every action available to the end users a check that queries to see if the background process is running (the background process could as its very first step set a flag, and then unset it as the very last thing it does). If an action finds the flag set it could then by-pass the normal processing, perhaps display a message saying that no processing can currently be conducted, and then exits the process immediately. This would meet the primary requirement which is to prevent the deadlock.

Alternatively you could set the visibility of your actions to include the value of this flag so that users are actively prevented from starting those actions.

For the second your home screen could be auto-refreshing a variable that is set to the value of the flag I mentioned above. Then you can use the value to display a section that is normally hidden that has the message you want to display. When the flag changes then the auto-refreshed variable would change and the section would disappear again.

There isn't a way to bring those two aspects into a single solution (e.g. a modal pop-up)

Thank you Stewart for your support, I think the flag approach might help solving our scenario will try this and let you know if this works for us