gnunet.org currently inaccessable - time-related error - renewing of expired certificate maybe necessary

Hello,

visiting gnunet.org via TOR browser gives this output:

Button next to URL bar: 'Not Secure' - Connection is not secure


'Your Computer Clock is Wrong

Your computer thinks it is 1/28/2023, which prevents Tor Browser from connecting securely. To visit www.gnunet.org, update your computer clock in your system settings to the current date, time, and time zone, and then refresh www.gnunet.org.

Learn more…'


My system clock is correct.


Clicking on Lean more gives leads to this website - https://support.mozilla.org/en-US/kb/troubleshoot-time-errors-secure-websites?as=u&utm_source=inproduct - of which this section fits the best to the reported issue:
'Contact the website owner

If you get a time-related error on a secure website and you have already checked the correct settings of your system’s clock, please contact the owner of the website which you can’t access and inform them of the problem. The website owner might need to renew the expired certificate, for example. '


Greetings,
Bastian Schmidt