Nowadays, more and more developers are trying to include "live service" aspects to their games to keep players' interest high for as long as possible. One way is to introduce time-limited events. Sometimes these are completely dependent on central servers over which players have no control, so these events will sooner or later be forgotten or impossible to play.

But fortunately there are DRM-free ways to implement them, such as those that are triggered when the computer calendar marks certain dates. As more and more games make use of them, and it's often worthwhile to see at least once what happens, I'd like to try to collect them in one thread that specifies the duration of the events and what can be expected from them.

I've created a preliminary spreadsheet with some games I'm aware of, but some data is missing and I'm sure many more games can be included, so everyone's help is needed.

If you know of any games with these characteristics, please write them in the comments and possibly specify event duration and what changes are made, thanks to anyone who would like to contribute!

GOG Games with Time-Limited Events

You mean like:-

Rise of the Triad (1994) - If you play it on 25th December, the soundtrack is replaced with Christmas tunes?

Ruiner
Play on Christmas day and there will be a Christmas tree decoration in the menu. If activated, you can play wearing a Santa outfit and use a candy cane as a weapon. screenshots.

Not really an "event" but calendar man in Batman Arkham Asylum provides different dialogue depending on the date.

ATOM RPG has or used to have(?) these optional seasonal events, like a Winter one last year, which I assume you can access retroactively by turning back (or forward) your system's internal clock, in case you missed them.

Not really a time-limited event but rather a secret seasonal mode, but Crusader: No Regret does this when you fire it up on or around the end year festivities. Apparently you can also force it via a cheat command, like the short "Merry Christmas, CHEATER!" message (at 0:27 seconds) would imply?

Unepic, if you play during the winter, will have snow in some areas, and will also have Christmas decorations around that time.

This example is notable because, at least in some versions of the game, at one point some of the files were missing from the GOG version. As a result, if you played the game during that time of year and attempted to go to the area with the winter theme, the game would crash. The work-around was to change the system time (or fake it with something like libfaketime).

The Adventures Of Johnny Castaway Screensaver

Johnny Castaway is stranded on a tiny island, and wants to be rescued.
When you watch over christmas, he has a christmas tree on the island.
When you watch over Halloween, he has a pumpkin.
It even changes from day to night, depending on your clock settings.
And you could fool your computer, by manually changing the date and time.

He spent his days fishing, reading, swimming, jogging, building a raft, lighting a bonfire, arguing with a seagull!
And he *almost* gets rescued so many times, but he always misses his chance!

I spent hours watching Johnny!

Craft the World has a Halloween and Christmas event every year (determined by the system clock) that changes food, decorations, armour and weapons depending on the season. Halloween also has a bonus game over its duration (1 every hour or so), where you have to kill a set amount of spooky enemies (witches/vampires) in a certain time, and receive bonus item crate drops if you succeed...

Good idea, thanks for creating a list. Trying to help:

-Grand Theft Auto Vice City - The Hyman Memorial Stadium is open only during certain in-game hours to participate on event missions

And not sure if this one fits your criteria:
-Defense of Egypt: Cleopatra Mission - Provides a daily reward: Gears (I don't remember if also considers gems, sorry)
Those are used to enhance your unit types on the workshop.
I didn't take the opportunity to figure out the exact logic but -my guess-: A 24 real hours elapsed validation every time you open the vgame based on the timestamp of the last time you closed the vgame
Would be easier to check changing the operating system timestamp accordingly, but you know... that would be also some kind of cheating... that's why I did not bother to try

House Party currently has Halloween decoration. On Christmas it will have different decoration (at least that was the case in the past years). There also is a Valentine custom story included in the game by default.

However ... the decoration do not depend on when you play it. Changing the date won't do a thing. The (regular) updates Eek relases have that content - or not.

So you can backup your offline installer now and play with Halloween decoration whenever you want.
It can be kind of a downer if you miss it.

Railway Empire suprised me with Halloween portraits of the corporate leaders (the one you choose/have to use included).

For the time being I don't know if it's enough to have the OS calander set up.

Terraria, IIRC changes and/or adds some stuff like Walls and Blocks around Christmas like Candys and so on.
edit: and even has christmas presents (boxes) as loot which you can open and get stuff out of it

Just a nitpick: I don't think VC fits here cause I guess OP meant those events which are based on real PC time and calendar, not ingame ones, otherwise the list will be bloated by games with their own mission schedule.

Unavowed:Nothing special in the game, but if you visit the memorial on 9/11, you get a achievement.
Meaning: You have to play the according mission on that day and go there. Well, that definitly counts as event. Play the game and visit calendar man on holidays marked in Calendar Man's calendar. He tells you a story about a crime he commited on that holoday.
There is an achievement for doing that on all marked days. Also after that his cell will be empty, he escaped.


btw, changing the computer's date lets you fake the events.

Serious Sam 4. It has a Halloween and Christmas thing. But sadly, it does not work in the GOG version, only Steam, because it is checking for Steam's server clock.