How to Create a Milestone Update on Your Facebook Business Page
If you’d like to add a milestone (either now or later) on your Facebook Business page, click the Offers, Events+ option and then choose Milestone in the status update box. The Milestone dialog box appears.
With the Milestone dialog box open, follow these steps to create a new milestone:
In the Event text box, type the name of the milestone.
(Optional) In the Location text box, type the location of the event.
Use the When drop-down list to choose a year for your milestone.
(Optional) If you want to include the month:
Click the +Add month link. If you choose to add a month, Facebook then gives you the option to add a specific date to your milestone.
If you want to include a specific date for your milestone, click the +Add Day link.
(Optional) If you don’t want this milestone to appear on the news feed of your followers, select the Hide from News Feed check box.
(Optional) To add a photo to your milestone, click Upload Photo and select a photo.
Click Save to complete your milestone.
When you create a milestone, it spans both the left and right columns of the timeline.
Milestones take up more screen real estate, so it's easy for your audience to notice them. Make your milestones pop by including relevant and interesting images.