The Harvest Moon is tonight (in Europe at least). The Harvest moon can be identified by its significantly earlier rising time after sunset compared to other moons. It's now.
If Ramadan means the rain after summer heat then that could be anytime. Unless there's some meteorological evidence that it always comes around the 7th full moon after the spring equinox in the region where Muhammad lived (Petra, Jordan)??
If Ramadan means the Harvest Moon then it's now. If Shahr means a full moon phase of 3 days then that makes Ramadan 2019 the 12th, 13th and 14th September.
I missed yesterday so am aiming for today, Saturday and Sunday instead, God-willing.