A support hold at 10:00 ICT on a quiet Tuesday is not the same event as a hold into the London open. We teach session context as part of level quality, not as trivia.
Thin hours can print tidy tests that vanish when the next centre arrives. Students who only study US session screenshots often overfit to those prints. In the evening clinic we mark the same pair at 08:00, 14:00, and 21:00 ICT and compare which levels survived.
If you trade from Bangkok, your calendar is an input. Public holidays in Tokyo, Singapore, and London change who is present. We keep a wall calendar in the studio for that reason; it is not decoration.
Use session stamps on every screenshot you bring to a private review. Instructors will send unmarked charts back.