How long after someone messages you would you message them back?

I messaged this guy I like about 2 years ago after he blocked me on messenger on a different profile. When he was trying to talk to me I was rude and want another chance. Do you think it’s past the time he could possibly reply? Based on his profile it seems he’s been occupied , so much so he wouldn’t care about me and my little message.
How long after someone messages you would you message them back?
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