Change a Date Field to a Birthday Field

To change a regular date (MM/DD/YY) field into a birthday (MM/DD) field, you'll create a new field, export your audience, replace the old date information with the new birthday information, and reimport your audience.

In this article, you'll learn how to make this change in your audience.

Create a new birthday field

In this step of the process, you'll create a new birthday field. Don't delete your old date field yet, because you'll need it to complete the process.

To add the birthday field to your audience, follow these steps.

1. Click Forms, then click Other forms.
   
   If you don’t see the Forms page, you may need to verify your email domain for your audience.
2. Scroll to the Form builder tile, then click Manage forms.
3. If you have more than one audience, click the Audience drop-down and choose the one you want to work with.
4. In the Forms and Response emails drop-down, select Signup form.
5. On the Add a field tab in the side panel, click Birthday.
6. On the Field settings tab, name your field. Name it something unique, so you can tell it apart from your current date field. You can change it later.
   
7. If you want new subscribed contacts to add their own birthdays, make sure Visible is selected. To hide it, click Hidden.
8. Click Save Field.

Export your audience

To export your audience, follow these steps.

1. Click Audience, then click All contacts.
2. If you have more than one audience, click the Audience drop-down and choose the one you want to work with.
3. Check the drop-down next to Email Address and choose Select all.
4. Click Export audience.
   
5. In the Export all contacts? pop-up modal, click Confirm export.
6. After the export is finished processing, click the Manage audience drop-down and select Export history.
7. Click Download CSV to download a copy of your audience.

The file is packaged as a ZIP, so you'll have to unarchive the file before you can open it in your preferred spreadsheet program.

Replace old data with new data

Date formats can be tricky, so check your documentation if you have trouble. If you use Excel, here's their date format help article.

To replace the data in your spreadsheet with formatting or by hand, follow these steps. In both examples, you'll create a duplicate birthday field column, but don't delete the old date column yet.

Change date column format

1. Open your CSV export file in your preferred spreadsheet program.
2. Duplicate your original date column, so you can edit it. If you're using column labels, label it what you named the birthday field in Mailchimp.
3. Highlight the new birthday column and open the formatting options.
4. Look for the Numbers or Date formatting options, and change the format of this column from MM/DD/YY to MM/DD.
5. Verify that the data looks the way you want it and save your CSV.

Change date column data manually

1. Open your CSV export file in your preferred spreadsheet program.
2. Duplicate your original date column, so you can edit it. If you're using column labels, label it what you named the birthday field in Mailchimp.
3. Prepare a column in the CSV with the new birthday field data by deleting the years from each entry, so it matches the format MM/DD.
4. Verify that the data looks the way you want it and save your CSV.

Update your Mailchimp audience

Perform an auto-update import to place the new birthday field in your audience. Match the CSV's birthday column with the new birthday field in your audience. On the Organize your contacts page, be sure to check the Update any existing contacts checkbox.

After the import is done, view your audience contact table. Check your new birthday field, and delete the old field.

If you have a paid plan, you can use a pre-built Customer Journey to send a promotional birthday email to subscribed contacts. If you've used classic automations before, you can send a birthday automation.