Mj, the pollen on philos comes out in the evening, sometimes late in the evening, of the second day the bloom is fully open. The bloom will close over the pollen shortly after so you have to be snappy if you want to collect it. My mecos (philos like P. bipinnatifidum, the tree types) put out pollen anytime from 8 PM to 11 PM, depending upon the species/hybrid. Others put out pollen around the same time range.
Some philo species seem not to produce pollen, which vexes me because how can a plant be a species and not produce pollen? My P. tweedianum doesn't produce pollen, is a species, yet has accepted pollen from other species/hybrids and set viable seed!
So in the hybridization game, you can never be sure!