The 12-hr time format is shown within the app on the calendar page, but when the user clicks on the event, it reverts back to 24-hr time format. I’d like to remain the same because many people will have trouble understanding exactly what time the meeting is, not having an understanding of this time format.
The date and time on the calendar layout uses the user’s regional settings on their device. So that same date will look different for someone in the US compare to someone viewing it in Europe. When you open the event and view the date, it is just showing the date as the text it is storing in the sheet. You can either adjust the formatting of the date by changing the formatting in the column in the sheet or using the new option to adjust the formatting in the data tab. Using the new option will display it however you want to the user, but it will still respect the region settings for each user.
https://docs.glideapps.com/all/reference/data-editor/untitled/date-time-formats