This is a great puzzle that probably ought to have been a Tuesday, but that doesn't really bother me. Really. The fact that I finished it in over 5 minutes is a tribute to the creating skills of the authors, not a reflection of my solving skills at all.
The theme is fun: the answers all have time periods in them, arranged in order from longest to shortest as you move through the puzzle. The phrases are all positive in connotation, thus the revealer is PRIMETIME. I'm not sure that the clue for REDLETTERDAY is exactly right. The definition from Wikipedia is a day of special significance or opportunity, so I suppose the date might be circled on a calendar, but it seemed just a bit off for me.
The puzzle really shines in the fill, though. Despite the abundance of 3-letter answers in the middle, there are few answers that felt questionable. HED is a bizarre partial from an uncommon phrase, and GOA is clued with a reference to Psycho instead of the classic crosswordese Indian state.
Leaving aside 1A (CBS - C-), those first three down answers showed me the quality of today's fill. 1D: More evasive with the truth (CAGIER) is great. 2D: Marilyn Monroe, notably (BLONDE) is also excellent, even though she, like many, was a bottle blonde. 3D: Something you reach out and take? (SELFIE) is brilliant.
Other nice fill include SCYTHE, RUBNOSES, MAILITIN. 41D: "You agree with me?", informally (AMIRITE) is cute.
My fave today is 61A: Substituted "math" for "mass," say (LISPED). My least fave is 48A: Concepts not meant to be questioned (DOGMAS). I don't like the plural on that. To me, it seems that "dogma" on its own encompasses multiple concepts typically.
P.S. Aha! It's a 16 x 15 grid. No wonder it took longer to complete.