Tapping the time does not open my Alarms/clock on Sony Marshmallow 6.1
This might be a useful discussion for the developer:
The clock app I have is com.sonyericsson.organizer v. 20.1.A.0.16 if that is any help.
I remember this working previously. Currently using 4x2 widget on Sony Xperia Z3 23.5.A.1.291 Android 6.1.