How can I use PHP to obtain the content after the specified text in a piece of code?

Get a piece of code without a class or id Identifier, as shown in the following code: name: xxxage: 22 height: 180 cmbirthday: How can I use PHP to obtain the date "birthday:" followed? This is not a fixed format, sometimes it may be 02-sep-... get a piece of code, there is no class or id Identifier, as shown below
Name: xxx
Age: 22
Height: 180
Birthday: 1900-01-02

How can I use PHP to obtain the date "birthday:" After?

This is not a fixed format, sometimes it may be 02-sep-1900 format.

Thank you !~

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Get a piece of code without the class or id Identifier, as shown below:
Name: xxx
Age: 22
Height: 180
Birthday: 1900-01-02

How can I use PHP to obtain the date "birthday:" After?

This is not a fixed format, sometimes it may be 02-sep-1900 format.

Thank you !~

Preg_match () regular match