I can reproduce this issue consistently each time.
Using Google Now to store a reminder (either via voice input or by keyboard) will correctly store the title and the date, but not the hour.
If I use the voice input, it recognizes the hour set properly and even displays it to me. After that, it asks if I want to save the reminder, I say 'yes' and it seems to be stored properly.
But when I go check it, it has lost the hour and it is set for the entire day.
Is this a known issue? Is there a fix? Can other reproduce this?
Motorola Moto g 3rd gen, Android version 6.0. If I'm correct, the Google Now version is 18.104.22.168.arm.