Gantt Diagram timezones issue


I’m trying to make Gantt’s diagram timeline to lie inbetween 7:00 and 23:00. I found out, that after setting at Gantt object


(where start and finish is 2019-11-22T07:00+03:00[Europe/Moscow]
and 2019-11-22T23:00+03:00[Europe/Moscow]
) the timeline appearence depends on a
But when the timezone is set to “Europe/Moscow”, the timeline on a graph goes from 08:00 to 00:00 (attachment 1)
Since the “Europe/Moscow” timezone parameters are “offset=10800000,dstSavings=0,useDaylight=false” I decided to try the timezone that has the same parameters, but the offset is less by 1 hour, which is “Africa/Mbabane”, for example (offset=7200000,dstSavings=0,useDaylight=false).
After applying this timezone to Gantt, the borders of the timeline went from 06:00 to 22:00 (attachment 2).

What should I do, to make the timeline lie in 7 and 23 interval? Any advice or opinion would be grately appreciated. Please help