Optional ReadonlybarsOptional ReadonlycalendarTrading hours: a session range counts this calendar's sessions.
ReadonlyendThe instant the range ends at, in UTC seconds: the clock when sizing a fetch, the latest bar when placing a view.
Optional ReadonlyzoneThe zone a month, a year and a date without a calendar are counted in. Default DEFAULT_TIMEZONE.
Bars already loaded, oldest first. Without a calendar a
sessionrange counts the dates they fall on, andallstarts at the first of them.