How to continue running total calculation to a future date

Hello,

I am attempting to calculate a running total of tickets based on a 'datecreated' up to the time a customer is expected to use them ('expectedstart').  The formula in the screen shot works fine up through 8/1/2023, which is both the most recent cloud data refresh and the most recent 'datecreated'.  The individual values continue to populate in the 'Tickets by Expected Start' column; however, the running total stops because the formula as it stands now is based upon 'datecreated' and not 'expectedstart'.  Would appreciate advice on how to modify this formula (or even a different approach) to begin a new running total for each new 'expectedstart' date.  For example, the first empty row in the right-hand column would read '66', the one below would read '137', etc.  The end goal of this effort is to produce a visualization that depicts the build-up of tickets purchased over time by each 'datecreated' up until the final total at the 'expectedstart' date.  Thanks in advance for your assistance.  Jim