Sending, receiving, and organizing email in Outlook.com
Hello, thank you for contacting the Microsoft Community.
Unfortunately, for security reasons, you can't find the creation date of your Microsoft account online or on your profile page. This information has been restricted for security reasons.
The only way to verify the creation date of your Hotmail account is to look for the welcome email from Microsoft that you received when you created your account.
For example, see the screenshot here.
To do this, access your @hotmail.com account at https://outlook.live.com/ and use the Outlook search bar to search for "welcome". Make sure the filter is set to "All folders" to ensure a complete search.
If you can't find the welcome email because it has been deleted, contact Microsoft Live Support for assistance. Because this information is confidential, sharing it on public forums can be risky, so it's advisable to contact a Microsoft support representative via live chat.
https://support.microsoft.com/contactus/
Let me know if you still need more help.