[harshreality]

Respectable CAs (perhaps that's an oxymoron) will email the contact email address ahead of time warning about the expiration.

[sdfjkl]

Respectable CAs will email you a warning about a month before it expires.

Disreputable CAs will email you 3-4 months before it expires, emphasising that you need to "ACT NOW" (GoDaddy is guilty of this).