A source told the JC: "Of all the things the royal staff have to consider, with the crazy schedule the King has at the moment, to move things around out of respect for the Chief Rabbi and Shabbat is quite a gesture.
"It wasn't like the Chief Rabbi's office told them Shabbat would be an issue. The Palace took the initiative and phoned up and said, don't worry about it, we have realised it will clash with Shabbat so we will move it for you.
"It was absolutely wonderful of them, and characteristic of the King."
Aside from the Chief Rabbi, Board president Marie van der Zyl is also attending the meeting later today.
King Charles has established a long and deep friendship with the Jewish community over many years.
Unlike Elizabeth II, he has visited Israel and has a strong sense of its achievements.
He has seen how Israelis have made the desert bloom, as well as become a leading force in both the worlds of high-tech and medical innovation.
In Britain, he has visited numerous Jewish institutions and is patron of organisations such as World Jewish Relief (WJR) and the Jewish Lads’ and Girls’ Brigade.
Last year, he gave a private donation to WJR that was entirely without fanfare.
The King has also shown acute awareness of horrors of the Holocaust and often met survivors.
Earlier this year, he commissioned portraits of Shoah survivors to be part of a permanent exhibition at Buckingham Palace.
And in March, he went to Winchester to unveil the statue of the leading medieval Jewish woman, Licoricia.
The King also has a deep personal connection to the Jewish community. His grandmother – Prince Philip’s mother, Princess Alice of Battenberg – was honoured as a Righteous Gentile for hiding a Jewish family in her home in Athens during the Nazi occupation.