This is GMMTV's first weeknight series in GMM25 (excluding re-runs). For the longest time, they've traditionally held the Sunday 2000H timeslot. But they started airing on Saturday nights last year ("Our Skyy" which premiered on LINE TV was the first, followed by "Theory of Love"). They even had a Saturday/Sunday night drama with "The Sand Princess", which I think was treated more like a GMM25 lakorn.
Over at One31, they often had the Saturday or Sunday night timeslot. But from September 2018 to December 2019, they held the Friday night timeslot. GMMTV had 2 dramas that aired on a Monday night - "Fabulous 30 The Series" and "Teenage Mom the Series" (which was also a LINE TV exclusive before it aired in One31).