I'm not sure if the term "gaslighting" fits here. This just seems like run of the mill lying and manipulating.

Victims of gaslighting are deliberately and systematically fed false information that leads them to question what they know to be true, often about themselves. They may end up doubting their memory, their perception, and even their sanity.

Gaslighting would seem like it'd be more that if they knew weekends were a thing befohand then you'd lie that they imagined it all (and that they might even be crazy for having thought that).