It seems that the function Calculate time difference, in Global Settings->Regional does not work, or may be I'm doing something wrong.
I tried in my own 2.4.7, and in , but the link just show 0 (zero). Even when here in Sweeden it's 09:56, and the server time is 12:56
Works for me. I remember having a similiar problem earlier, though - but I cannot reproduce it anymore.