The awaiters' code

For a few decades, five of us have been been observing the interactions of certain shady people, trying to be sure that there is no danger in their beliefs, conspiracy theories, and critics towards the granter; you'll see, almost every employee has some sort of objection to something every so often, and it's usually open and constructive to some extent, but something about this guys is... not okay.
But, as much as I fail to understand most of their beliefs, back when they still met at the Underground Library the words made sense together. I understood what they said, and oftend disagreed and thought those ideas could lead to bad places. That was that.
Now that they don't have regular meetings (not that we know, and not in the library) when people of that group interact, there is always some sentences that don't make any sense. They plan to go on a hike to places where that is impossible or at least life-threatening, send regards to relatives the other person don't have, or recommend books, songs or movies that don't exist. They even talk about their last vacations in a world when only one of them has been.
We have detected several words that they use for particular circumstances, here is a few of them:

I don't think that they have lost their mind or that they are confused about whom they are addressing, right? It has to mean something, and people don't invent a whole secret language to talk about the weather. But Gael has yet to crack the code, or even confirm that there is one. Maybe when they are being literal when they that they will meet to eat icecream in a place where is always winter, and when they agree to leave a present for a common friend in the haunted houses. Maybe they are just... daring, and it's true that they are exploring the dessert.

Dictionary

3 Words.

Used by

A shady group

Structure

It's designed to seem like a regular conversation and to fit with the native languages of the speakers in suchs way that it isn't noticed by the interpreter.

Common Phrases

"See you tomorrow!"

Their usual way to say goodbye. Some might do a slight emphasis at tomorrow.
Not exactly a rare expression, and I don't think it's used to disguise anything, but to remind each other about one of their core beliefs: that the company's time loop most be broken. The implications of that keep the granter awake once in a while.

Specific dates

We are still trying to figure out which calendar they use, but there is no doubt that they are translating the system dates used to file orders and clients' files (basically the day number from the first day off the time loop followed by the exact time of the day) to it's equivalent out of the loop.

I have this nagging feeling that I'm familiar with it... Maybe that's because similar calendars are used in many worlds, except that it seems—to me, at least—that something is missing.