If you are editing your tree in Family Tree Builder software, please do the following:
1. Open your tree in Family Tree Builder.
2. In the upper menu bar click on ‘Tools’ and select ‘Options’.
3. Select ‘Dates’.
4. Change the date format to the one that is suitable for you.
If you are editing your tree on the family site online, the date display format on the site can't be changed manually. It will be determined by the site’s display language.