Paul G wrote:
1. Can anyone point to a reference to the fact that these regions used a different time zone than their neighbors?
I think I got that from Shanks. His International Atlas (4th edition) says that Zaporožje (his preferred spelling; 47N50, 35E10) uses his Ukraine Time Table 18. TT#18 differs from the usual one (Time Table 1) for post-1970 Ukraine timestamps in that TT#1 did not observe DST in 1990 or 1991, switched from +03 to +02 on 1990-07-01 at 02:00 and then began using DST in 1992, whereas TT#18 observed DST in both 1990 and 1991 and switched from +03/+04 to +02/+03 on 1991-03-31 by not adjusting the clocks that day. As far as I know, Shanks is the only source for this information. Given that Shanks has been unreliable in the past, the info could well be wrong.
3. Is there any clarification as to the geographic extent of the zone? Does it cover Donetsk as well? What part of Lugansk counts as "eastern Lugansk"?
Oh, for that one would need to carefully consult Shanks's tables that map geogralphical locations to time tables. They're about six pages of verrry small print in 3 columns on 8.5x11 paper, so it's not something one would want to do casually. I don't remember exactly, but my guess is that I just eyeballed them and tried to characterize them generally, way back when, and possibly Shanks did something similar when he came up with the tables in the first place.