Thank you for this feedback! Fortunately, this feature already exists. Just drag and drop items in the order you desire.
Let me know if you have any more questions on this!
Thanks to everyone who volunteered for testing the Office 365 group calendar. The TAP team will be reaching out as we are closer to being ready.
~AlexSteve Ball commented
Can't you just expose the Group Calendar? Having more than one calendar would also help
Sorry for the delay on an update on this one! I’m hunting down the status for you and will update once I have it.
Also, if you are interested in participating in testing or surveys for this, just tweet me at @skprufo.