Once of the recent changes in Office 365 that I have not tried yet is the new user experience for the user profile in Delve that makes really easy to update profile data using a very intuitive and agile UI:
To try the new user experience, just navigate to Delve in your Office 365 tenant and click the “Me” link. In the “Me” page you will see a new visualization of your profile data and some shortcuts to updating your profile information. You will also see items coming from your calendar in Exchange Online (EXO).
If you press “UPDATE PROFILE”, you will access the new profile page experience for updating your profile data.
For instance, you could click any of the sections and start updating your relevant data such as your birthdate.