Start here: This is a good overview of understanding dates (which are times). Getting your head around this will accelerate your development a lot:
Also, while the presentation layer date stuff in Bubble is great, there’s not much you can do on the backend and this is a source of frustration initially. (For example: need to turn a date/time range into an array of date/time slots? Can’t be done in vanilla Bubble. So, send it out to an API OR do it in the page.)
This will change once one can load moment and moment-Timezone in the server, but this is not yet a thing that can be done.)