Chaotic raid bonus time- How does the timer works?

[Jeeqbit]

Oh I am aware of the wonky distribution of Demimateria unfortunately, I wish they could change that for the next Chaotic, it was more about the timer, when does it appears, what triggers it, if it's not at the same time everytime, then surely it must be a rotation? Because seeing it at a certain time for multiple day in a row, then at a different time the next day, it's pretty confusing
I only care about it because it increases chance of Dais/minion/haircut drop

There are two ways they might do these things:

A daily seed (programmers know what this is).

An excel table with pre-determined values that it rotates through or selects in a particularly way. There is one example with Island Sanctuary where they rotated through it in a pre-determined order that has already looped now (so we know what the values for the workshop will be months from now).

They rarely use true RNG in this game for things like this. They really like spreadsheets.