Act 2 is where the identity of a perfume lives. If you have never worn a fragrance past the first hour, you have never actually smelled it.
ACT 01 | 0–60 MIN — Top notes present. Fresh, bright, volatile. The preview.
ACT 02 | 2–5 HRS — Heart notes: florals (rose, jasmine, iris), spices (cardamom, pepper, cinnamon), green materials, certain woods. Medium volatility. This is the main character of the formula — the personality the perfumer built. Heart notes typically make up the largest portion of a formula by volume in the 30-30-30 construction framework, and they determine what the perfume is, not just how it opens.
ACT 03 | 6–12 HRS — Base begins emerging in Act 2's later stages — a blending of heart and base creates the transition period between 3 and 6 hours that gives the formula depth and continuity.

WHAT TO DO INSTEAD
To force-smell Act 2 without waiting the full hour: apply fragrance to a blotter and leave it for 45 minutes before smelling. The top notes will have departed and the heart will be accessible. On skin, the 30-minute mark is the earliest reliable entry into Act 2 territory. When comparing fragrances, always compare at the same time interval — Act 2 versus Act 2, not Act 1 versus Act 2