Team Fortress birthday?

[Silikone]

In Team Fortress 2 and Team Fortress Classic, party mode is activated on the game's birthday (two days left!). I found birthday content in Team Fortress 2.8. I looked at the source code to see how events could happen depending on the date. I don't have experience in programming, but it seems like there is some kind of menu to activate birthday mode instead of using a date.
How do I access it?

[Baker]

In Team Fortress 2 and Team Fortress Classic, party mode is activated on the game's birthday (two days left!). I found birthday content in Team Fortress 2.8. I looked at the source code to see how events could happen depending on the date. I don't have experience in programming, but it seems like there is some kind of menu to activate birthday mode instead of using a date.
How do I access it?

Well, to the best of my knowledge Team Fortress 2.7 was the final version.

However, that being said, Team Fortress 2.5 was the last open source version as far as I know. You could check the Team Fortress 2.5 source.

http://quake-1.com/quakec-gallery/tf25src.zip

It is possible that this Team Fortress 2.8 is one of the many non-official updated versions made by the many different TF enthusiasts and may be open source.

[R00k]

Party mode - TF2 Wiki

"Party mode is the successor to the birthday mode in Team Fortress Classic and is activated on servers that have disabled blood. It is used to celebrate a player's birthday, festive occasions or simply for fun.

Like in TFC, TF2 automatically turns birthday mode on when a server's clock hits August 24th, the release date of the original Team Fortress (1996). " --http://tf2wiki.net