city VARCHAR,
start INTEGER NOT NULL, -- timezone-less timestamp (Unix Epoch)
end INTEGER NOT NULL, -- timezone-less timestamp (Unix Epoch)
- day_change INTEGER,
+ day_change INTEGER, -- in seconds after midnight
timeslot_duration INTEGER,
utc_offset INTEGER DEFAULT NULL, -- if known, conference UTC offset in seconds (e.g. CET = +3600)
display_time_shift INTEGER DEFAULT NULL, -- if not null, add number in seconds to conference times when showing times