From start to finish, 3 weeks or so. First bud to open? Seems somewhat random to me--but you know, i never paid attention to that...

Oldest flowers, closest to the leaves. Phal flowers can last weeks and the spike can continue flowering for months.

You are correct, you don't know how long it was flowering. Also, the change from a greenhouse environment to a store, then house, can cause the buds to drop. Dry air in the house will effect the buds.

Jane

It is really remarkable when they bloom for over a month. I had a couple do that this last summer. What a treat!

You're in zone 6, which has been (until just the last few days) suffering very low temps. If you purchased the plant recently, it might have gotten a chill on the way home.

Birdie, I've had them last almost 6 months...they were collecting dust.

Jane

I've had individual Phalaenopsis flowers last anywhere from a few weeks (equestris flowers + some smaller hybrids) to a few months (larger, more robust hybrids) - it all depends on the genetics. In my experience, the buds generally open along the spike from closest to the leaves to the most distant, but there are exceptions.