Google Calendar Booked Event Timeslots to find Empty Slots

Hello Folks,
My usecase to to extract the Timeslots that are booked on google calendar & find out the available slots for the rest of the day?

I have tried multiple plugins on bubble & here’s the JSON format which Google Calendar returns the values

I am able to extract the start time or end time for all the events, but not both into a single database entry

Lets say even if I save them to two columns in a DB, how do I get them concatenated to a single DB column with pairs, If this can be done, I can at least convert the timestamps into unix format and find the empty slots

Please help if you have any other alternatives
Thankyou so much in advance