Is there a way to schedule when the email will be sent?

@user_ahpvqg 

In a word--------no.  Comcast email has never had that capability.  If you are referring to Yahoo, where your email is going to be migrated to, again-------no.  Yahoo has never had that ability either.  Fastmail has it, and if you have a Microsoft 365 account, Outlook.com has it (I think).  Some email programs may have extensions available that provide that capability.

@user_ahpvqg 

When I create an email, is there a way to schedule the date and time when the email will be sent?

Some third party email apps may have a Send Later function.  Thunderbird has a Send Later add-on.