A feature that allows users in the U.S. to participate in GroupMe chats via standard text messages, without needing the app or internet access.
I cannot provide specific instructions on changing your date of birth as it may vary depending on the platform or service you are using. Generally, you would need to go to your account settings or profile settings on the respective service and look for an option to edit your personal information, including your date of birth. If you are unable to change it yourself, you may need to contact customer support for assistance.
References: