I can use `mailto` to send an email. Is there a similar technique to insert an outlook calendar event

I am struggling with these 2 links. They both allow events to created in Outlook via a href link.

This first link works fine. The date in UTC format, 2023-03-24, starting at 09:00 and ending at 10:30 on the same day

https://outlook.office.com/owa/?path=/calendar/action/compose&startdt=2023-03-24T09%3A00%3A00%3A000Z&enddt=2023-03-24T10%3A30%3A00%3A000Z&subject=Placeholder&rru=addevent

When I follow this link above, it creates an event in my calendar at the expected time and date

This link is the same other than starts 2023-03-31, starting at 09:00 and ending at 10:30 on the same day

https://outlook.office.com/owa/?path=/calendar/action/compose&startdt=2023-03-31T09%3A00%3A00%3A000Z&enddt=2023-03-31T10%3A30%3A00%3A000Z&subject=Placeholder&rru=addevent

When I click this link, it creates a link 1 hour late, from 10am until 11:30 on the 31st.

I don’t understand the behaviour or what I need to change