Just looked it up and you're right. It was 0.02 seconds. 748 days aboard Mir over several missions. https://www.amnh.org/exhibitions/einstein/time/time-travel#:~:text=Cosmonaut%20Sergei%20Avdeyev%20spent%20a,he%20never%20traveled%20in%20space.

There is also a YouTube video about it on the "Half As Interesting" channel.