Seems like a good idea. People would probably rather work longer hours during the week. The long break would give plenty of time for family, worship, rest, sport, the arts, recreation, volunteering, & travel, for example, which people would doubtless appreciate, and there would also probably be less sickness in society. However, if people were not willing to work longer hours during the week, it might be no good because Israel, like every country, would still need to be sufficiently productive and keep the economy going.
Palestinian man suffers light wounds from rocks thrown by Jewish men in Jerusalem (Haaretz)
from the article: Netanyahu to consider shortening Israel's work week to four days