Revert "Merge pull request #12564 from gitmai/bug-880775-birthday-timezone"

This reverts commit 9d1a9fe8c40519f2bf7b558790a4df4d5b818ca3, reversing
changes made to 893bcd450ba60886a711e26a11d73aa3e88a1ee5.
Merge pull request #12630 from lightsofapollo/revert-9d1a9fe

Revert "Merge pull request #12564 from gitmai/bug-880775-birthday-timezo...