After looking into the matter some more, my impression is that in practice East Jerusalem clocks are in an unsettled state, in that some are set to Israeli time and others to Palestianian time. For example, here's a story in Roger Friedland and Richard Hecht's book _To Rule Jerusalem_, (University of Calfornia Press, 2000), page 289: We arrived for our appointment at Nusseibeh's office promptly at 9:30 on Monday 22 May, 1984. The big clock in his office showed 8:30. We checked our watches, thinking the electricity had stopped functioning in East Jerusalem or perhaps his clock was broken. The clocks were working fine. Israel had just introduced daylight saving time. Nusseibeh's office, like all other Palestinian institutions, refused to set its clocks forward. and another story about the spring 1989 transition (page 327): In East Jerusalem, policemen would ask Palestinians for the time. If they answered according to Palestinian time, their watches were sometimes seized and smashed with billy clubs. One Palestinian from Silwan who answered, "Four o'clock" was made to stand in the street for an hour until it was 4:00 P.M. according to Israeli clocks. If the official time in East Jerusalem is Israeli, but many people observe Palestinian time, it would be problematic to use it as the canonical location for the West Bank daylight-saving rules. It might be better to pick the most populous location in the West Bank where there is a reasonable working consensus about the time of day.