QuickBooks Online has various automation features that could lessen your work, manish4.
Currently, the system can only set a scheduled email but unable to set the time. I know it's ideal to have this option in QBO, so I'll be taking note of your feedback and share it with our developers as they're always looking for ideas from users on how to improve our software. That way, they might consider adding it to any future product enhancements.
In the meantime, I recommend visiting our Blogsite to keep updated with the features and enhancements that our developers are currently working on.
Check these customisation-related articles for additional guide and reference: