Understanding fading
Why do floral perfumes fade quickly
A floral perfume may seem shorter-lived when the flower-like impression becomes less distinct. Supporting notes can remain, and different floral compositions do not share one duration simply because they list rose or jasmine.
A HUME Fragrance buying guide
Follow the whole structure
Read the supporting woods, musks or warm notes. The perfume can develop away from an obvious floral opening without becoming entirely absent.
Describe the flower impression
Fresh petals, richer flowers and softer powdery textures are different references. Write which one changed so another trial can answer the same question.
Keep observations separate
Record your own later impression apart from any willing observer's description of presence. Those reports are useful context rather than identical measurements.
Try this before you buy
Note the changing floral character and the remaining overall scent during a repeat appropriate wear.