In the game, for example, 'anniversary_25', 'anniversary_40', 'anniversary_50', there are events that are triggered after X years.
As another example, in the case of 'sister_group_delay', there is a time condition that is triggered one week after the group is created.

If you look at these events, you can see that there is an event that is triggered by a certain time condition, but if you actually check it, you can confirm that the condition does not have any condition related to any time variable.

Also in MOD documents, time-related variables could not be confirmed. The only time-related variable was the season.

So what I want to know for sure is... ...
Are these events triggered by conditions hard-coded in the game?
Is there no way now that users can implement this time-related MOD?