Now days due to strong hold on security many Facebook features are disabled or made more features less so that there is not scamming on there network and everyone can browse Facebook as they earlier wanted too. So now if you wanted to change your birthday date on Facebook you might not be able to because the profile editing option does not allow or give you any option to do that. But still if you really need to do that we have a simple trick for all of you.
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You just need to visit Facebook DOB Updating page and than you will see page like above just enter your new date of birth and a nice reason for changing and click on Send. Now you will receive an email from Facebook saying that they have received your request and they will process it and you will receive your change soon.
Hope this works for you all, make sure if it convinced you just share it with all your friends have fun and enjoy guys.