All you have to do, to extend your trial period, is change number in TrialKey element in application.xml. This file is located in /Library/Application Support/Adobe/Adobe Photoshop/AMT. You can navigate there with this command:
cd /Library/Application\ Support/Adobe/Adobe\ Photoshop\ */AMT
Then you have to open the file and edit it. You can use just TextEdit app.
open -a TextEdit application.xml
Now find the TrialSerialNumber Data key:
<Data key="TrialSerialNumber">911997074887979240115317</Data>
And increment this number by one:
<Data key="TrialSerialNumber">911997074887979240115318</Data>
And that’s it. Now when you relaunch Photoshop you will be prompted to login and you should see fresh 7 days of trial.
Just for the record. This 100% works but you need the 2018 versions, doesn't work on anything after (or potentially before?) that. I have the 2018 version and it works fine for me. Hopefully I can write something to automatically change the xml file when I boot up my pc or something just so I don't have to think about it. . .
You can find the 2018 versions below. You will still need to download creative cloud and make an account through the official adobe website.
https://prodesigntools.com/adobe-cc-2018-direct-download-links.html