Currently, the views order all-day events based on their index in the events array. However, in the Month view, all-day events are arranged by start date, from earliest to latest. This means that if events start at different times, they will be displayed in that order.

For example - https://stackblitz.com/edit/angular-yvtoyp?file=src%2Fapp%2Fevents-utc.ts,src%2Fapp%2Fapp.component.ts

Day view:

Month view:

Example - https://stackblitz.com/run/?file=src%2Fapp%2Fevents-utc.ts,src%2Fapp%2Fapp.component.ts

React seems to render them in the start date order - https://stackblitz.com/edit/react-kms53j?file=app%2Fshared-sc-events-utc.js

And Google Calendar for reference: