Thank you Kristen for your help.
I am using alfresco as a developer. and I need to change the time for the end users. users are getting emails at midnight and they want to get these emails at different time. There must me some way or need to make changes somewhere in the code or some file. I am not able to find out that. I have tried "corn" in alfresco-global.properties file, but it didn't worked.
kindly help me with the same.