node1 in the last 6 months it's always been 4PM Central Europe time, which means it was either 3PM UTC (during daylight saving time) or 2PM UTC (now that DST has ended).
However I'm open to changing the time if there's more demand for other periods. I did a survey last year which indicated Sunday afternoon (local time) was the preferred option. I'll probably do another survey later this year to check if there are other preferences.
I try to always schedule the live streams at least 24 hours in advance so people can automatically see the time in their own timezone by visiting the YouTube video page.