Assuming that you have all the dates from minimim of create date to maximum of change date in field DateNum.
Use below code.
num(create_time) & '|' & num(change_time) as KeyFromToDate
num(create_time) as Start,
num(change_time) as End
Start & '|' & End as KeyFromToDate,
Drop Table TempIntervalMatch;
This will create a intermediate table between Tickets & Master Calendar so that you will have id corresponding to every date between start date & change date.