I have a Outlook.com mail account with my contacts in the "all contacts" folder, which can be found on the "People" tab in outlook.live.com (online via a web browser). Some of my contacts have a birthday set.
I use the birthday calendar feature of outlook.com, which automatically generates a read-only "Birthdays" calendar and recurring all-day birthday events for my contacts that have a birthday set. The recurring birthday events have a default reminder time of 18 hours before the event.
I'm using my outlook.com mail account together with the Outlook desktop application. I get the birthday reminders at the specified time, 18 hours before the event. I would like to change the reminders on a per-contact basis. I.e.: for some contacts, I don't want reminders at all, while for others, I would like to configure a different reminder time.
When I try to change the reminder time in my Outlook desktop application, I get the error message "You cannot make changes to contents of this read-only folder."
When I open the birthday item in outlook.live.com (online via a web browser) by navigating to the Calendar | Birthdays, clicking on a birthday to show the popup box and then clicking on Edit, I get a form to edit the contact - which doesn't have an option to edit the reminder time.
How can I change the reminder time of a birthday event?
Note that this issue is specific for contacts in outlook.com mail accounts together with the read-only birthdays calendar and events that are generated automatically by outlook.com. The issue does not occur for contacts & birthdays in Office 365 work- or school accounts or for manually created birthday events in outlook.com. Many solutions that I find online apply to these other cases and don't work in my case.