Auto response in channel

Hi, sorry for the noob question, I've been googling for this but haven't been able to find the right answer.

I'm trying to enable a auto-response in a channel whenever people write after hours. So, after 6pm, I want to have a bot that whenever someone writes in the channel, an auto-response comes up like "We will review your request tomorrow starting from 8am".

Can the slack gurus in here guide me on how to do this? Thanks in advance!

PD: I'm part of an organization, so I don't have access to manage the workspace, just my channel. In case this is important.