Task: Due to some Urgent basis I want to prepone the Reschedule Time Event from 24 August to 23 August at 09:30 AM .
Steps:
Open the Reschedule Timing Event 
Click on the Edit button at the top right of the screen
Go to the Dates section 
Set the Date to 23 August
Click on the OK button at the bottom right corner of the pop up
Click on the event Start time section
Set the hours to 09
Click on the OK button in the pop up
Click on the Save button at the top right corner of the screen
Select the Send option in the pop up